A PoA has to be registered. If she is terminally ill then  someone can come to the house for registration of the PoA.

She can execute a poa for the same too. Yes registration can be done online from her residence too

Specific power of attorney has to be executed by your aunt in favour of family member to sell the property 

2) if she is bed ridden approach sub registrar office in your city to depute a officer to her residence for purpose of registration purposes 

Act as mentioned herein above 

Submit an application  to District Registrar, Mumbai with medial record of  aunt and document to be registered seeking visit of  official from office of Sub-Registrar for Sub-Registrar for document  registration. District Registrar will direct the Sub-Registrar to do the need for on payment of expenses.

Office address can be  downloaded from Government of Maharashtra website. 

If she is not able to go to the registrar's office to sign the papers for registration, then you can call the sub registrar to her residence to register the document at her home after paying the prescribed fee for the purpose and fixing an appointment with the concerned registrar.

Nobody will come to your home to get the registration done

\You have to apply for registrar's visit with the relevant documents about her health and immobility as well as by paying the fee prescribed for the purpose and then bring the sub registrar to your house in order to enable him to witness the signature of the person registering the document before him at her house. 

1. If your aunt can't be physically present in the jurisdictional Sub Registrar's Office to execute the POA in favour of Attorney, on certain fixed fees, the Sub Registrar will come personally to her residence and facilitate the execution of POA by her.

2.  The prospective Attorney to be nominated by your Aunt can physically go to the jurisdictional Sub Registrar's Office and explain the situation to the official and after payment of the statutory fee, the official will personally visit your aunt's house and conclude the registration of POA.

You need to request the sub-registrar in writing for making arrangements to register the PoA at your aunt's residence, clearly explaining why she cannot attend the registry in person for the purpose of registration.

Dear Client,

                A sub-registrar can verify and register agreements at the residences of buyers/sellers if they are on the death bed or are physically unfit to travel to the registration office. But in the past few months, owners have alleged that the sub-registrar did not visit their residences and their properties were transferred on forged documents and signatures.The authorised signatories for the seller and the purchaser, have to be present along with two witnesses, for registration of the documents.

Thanks & Regards

- Since, she is unable to move to the registrar office , then the person who is getting GPA , can move an application before the Registrar for taking her signature and other necessary completed after visiting the house of your aunty .

- An extra amount may be charged for giving this services by the registrar.