Registration is necessary only if you want to sell the property .for operating bank accounts notarised POA should suffice 

2) get medical certificate from psychiatrist that mother is mentally fit 

Only if any property rights are transferred in your name movable or immovable then registered POA is needed otherwise not needed

POA for bank and demat work does not have to be registered.. but registration makes it much stronger and safer for future use... Since her condition may worsen a fresh registered POA with clear financial powers is advisable... Getting a psychiatrist certificate confirming she is mentally sound on the date of signing is a good legal safeguard and can help avoid future disputes with siblings...

This poa may not work 

It appears there's a possibility of your sibling raising disputes despite you holding a poa from your mother 

The sibling may argue that the mother was in no mental state and condition to grant a PoA and thus you by taking her poa has played some mischief and misused your mother's assets 

In such a situation it is advisable to file a writ petition in the High Court for apponting a guardian of your mother under the Right of persons with Disabilities act

You can pray for a court appointed guardian who can jointly manage the assets of your mother with you

This will also allay any apprehension of foul play that your sibling may have against you 

Since the assets would be managed by a court appointed officer jointly with you there would be next to nil chance of any foul play for usurping the mother's assets

A POA given for the purposes of bank transaction need not be executed by a registered document, the notarised POA is recognised as legally valid. 

However in your case registration is advisable because of the issues viz., Progressive neurodegenerative disease,possibility of later disputes by siblings and for long-term dependence.

A registered document carries higher evidentiary value in court in the above circumstances. Many banks freeze accounts later if PoA is only notarised, especially after illness worsens.

Banks insist on specific account number. A vague clause like “operate bank accounts” is often accepted initially but later questioned.

A medical certificate issued by Psychiatrist or Neurologist stating that she is mentally competent, that she understands the nature and consequences of executing a PoA with the date of examination would be a strong evidence to challenge any dispute in the future. 

Therefore it is advised to do the following:

Execute a fresh detailed  and registered PoA

Mention specific bank/demat details, 
Obtain psychiatrist/neurologist mental capacity certificate,
Use independent witnesses and 
if possible to have a Video record execution.

1. As you already have a PoA which empowers you to operate bank accounts, even without mentioning the account numbers, you are legally authorised to do so. There's no need for a fresh one. But, it needs to be compulsorily registered, and not merely notarised.

2. Though not absolutely necessary, it is preferable.

Your situation needs to be handled with foresight, because the combination of a progressive neurological illness and future financial management is exactly where disputes tend to arise later. I will address both of your questions clearly and practically.

For managing bank and demat accounts, registration of a Power of Attorney is not legally mandatory, even for long-term use. Banks and financial institutions accept notarised PoAs, and in fact many banks have their own internal PoA formats. However, registration significantly strengthens the document from an evidentiary and challenge-proof perspective. A registered PoA carries a statutory presumption of authenticity, date, and execution. In contrast, a notarised PoA can be questioned later on grounds such as coercion, backdating, or lack of capacity, especially if the principal later becomes incapacitated or passes away.

Given that your mother’s condition is progressive, registration is strongly advisable, even though not compulsory. It does not “extend” the legal life of the PoA (a PoA always ends on death), but it makes it far harder for anyone to allege that the document was fabricated or misused when her condition worsened. From a litigation-risk standpoint, a registered PoA is substantially more defensible than a notarised one.

Your existing notarised general PoA that says “operate bank accounts” is legally usable, but it is not ideal. Banks increasingly insist on:

• Specific powers (operate, sign, withdraw, close, invest, redeem)
• Identification of institutions (banks, demat, mutual funds)
• Sometimes even account numbers (or at least authority to operate “all present and future accounts”)

You should therefore execute a fresh, detailed PoA, preferably registered, clearly authorising you to manage all present and future bank, demat, and investment accounts, sign forms, comply with KYC, and interact with institutions on her behalf.

On mental capacity, this is where you should be proactive. While the law presumes capacity unless proved otherwise, medical documentation obtained at the correct time is extremely valuable if a sibling later alleges undue influence or lack of understanding.

Since you have already noted communication difficulty but intact cognition, it is prudent to obtain:

• A psychiatric or neurologist’s certificate stating that your mother is of sound mind, understands the nature and consequences of executing a PoA, and is capable of making financial decisions.
• The certificate should be dated close to the PoA execution date.
• Ideally, it should be from a government hospital or well-established medical institution.

This is not legally mandatory, but it is one of the strongest shields against future disputes. Courts give substantial weight to contemporaneous medical opinions when capacity is questioned later.

Additionally, for extra protection:

• Ensure the PoA is executed in the presence of independent witnesses.
• Avoid being the only person present at execution.
• Keep video recording of execution if feasible (this is increasingly accepted as corroborative evidence).
• Ensure the PoA clearly states that it is being executed voluntarily and without pressure.

One important legal clarification: a PoA allows management, not ownership. You must not mix your funds with hers, and all transactions should clearly be for her benefit. Maintain clean records. This protects you legally and morally.

In summary, while notarisation may work in the short term, a registered, detailed PoA plus a contemporaneous mental capacity certificate is the safest structure in your circumstances. It significantly reduces the risk of later challenges by siblings and gives you operational clarity with banks as her condition progresses.

- The said notarized POA can be accepted by the Bank for the purpose of operating her bank account 

-  You can take a medical certificate for her affirmation that she is executing the POA in her sound mental status

Dear client,

In the instant case, it is strongly advised to have the PoA registered. The whole purpose of PoA is to maintain the financial transactions of the principal by the agent even at times of inability of the principal. In the aforesaid case, due to the ill health of your mother, a PoA is necessary for managing her financial transactions and the same for having validity is always advised to be duly registered since most banks and other institutions these days have made a compulsory requirement for registering the PoA.

Also it is important to note that though a mental capacity certificate is not necessary in most cases however it does prevent any kind of legal hassles as well. So it is advised to also get a mental capacity certificate.

I hope this answer helps. For any further queries, please do not hesitate to contact us. Thank you.

Under your given circumstances, it will be advisable to get the said POA registered by commissioning the said Registration i.e. Registering it by the Registrar visiting your premises.

For bank and demat accounts, a Power of Attorney is not compulsory to be registered, but registration is always safer in long run.

A notarised PoA is legally valid, but many banks later raise objection if health condition worsens.

Registration makes the PoA more strong and difficult to challenge by anyone in future.

Account numbers are not mandatory if PoA clearly mentions operation of all present and future bank accounts.

Since your mother’s condition is progressive, it is better to execute a fresh registered PoA now.

If she is mentally sound, this is the correct time to complete all formalities.

Mental capacity certificate from a psychiatrist is not compulsory but highly advisable.

Such certificate helps avoid disputes or allegation from sibling later.

Courts and banks give weightage to medical proof of sound mind.

Registered PoA with medical certificate gives maximum legal safety.