First, about the claim that from 2026, sisters’ NOC is compulsory in Mumbai and no probate is required.
There is no law in force or notified for 2026 in Maharashtra or Mumbai which makes it compulsory to obtain sisters’ NOC for transfer of property when a valid registered Will exists. There is also no law abolishing probate for Mumbai properties. Any statement that “from 2026 probate is not required” or “NOC from sisters is mandatory” is incorrect as of today.
In Mumbai (which falls under the original civil jurisdiction of the Bombay High Court), probate of a Will is still legally mandatory when the Will relates to immovable property situated in Mumbai, regardless of whether the Will is registered. This position continues unless and until the law is formally amended and notified — which has not happened.
If a Sub-Registrar is asking for sisters’ NOC, it is an administrative practice, not a legal requirement. Administrative practice cannot override succession law.
Now, on the flat purchased by your mother using sale proceeds of property gifted to her by her father.
If your grandfather gifted the property exclusively to your mother, and she later sold that property and used the proceeds to buy a flat in Mumbai in her own name, then:
• That flat is your mother’s self-acquired property
• It does not retain the character of ancestral property
• Your aunts (mother’s sisters) have no claim whatsoever in that flat
Once a gift is validly made and accepted, the donor’s other children lose all rights in that property forever. The source of funds (even if ancestral earlier) becomes irrelevant after a valid gift.
If your mother has left a Will giving that flat to her sons only, sisters cannot claim any share, even if they are not mentioned at all.
Now, regarding your father’s HUF and exclusion of sisters.
Under Hindu law:
• Daughters are coparceners only in ancestral HUF property, not in self-acquired property
• Your father’s self-acquired assets (cash, FDs, stocks, PPF, mutual funds) can be freely disposed of by Will
• If your father’s Will is probated and gives:
– only cash to daughters, and
– the rest to sons,
then daughters have no further claim beyond what is written in the Will.
They cannot demand equal share in:
• FDs
• shares
• PPF
• bank balances
as long as these are self-acquired assets and the Will is valid.
If the property or assets were true HUF ancestral property, then daughters would have a coparcenary share. But you have clearly stated:
• Father was Karta
• Sisters not made Karta (irrelevant anyway)
• Assets disposed through a probated Will
That means the assets were treated as father’s separate estate, not joint coparcenary property.
Now, on probate — cost, time, and chances in Mumbai.
Probate in Mumbai is:
• Filed before the Bombay High Court (Original Side)
• Mandatory for Mumbai immovable property
Costs (approximate):
• Court fees: up to ₹75,000 (capped in Maharashtra)
• Advocate fees: varies, usually ₹50,000 to ₹2.5 lakhs, depending on contest
• Miscellaneous expenses: citations, publication, affidavits
Timeline:
• Uncontested probate: 6–9 months
• Contested probate: 2–5 years, depending on objections
Chances of success:
If:
• Will is properly executed
• Testator had sound mind
• Attesting witnesses are available or affidavits exist
• No coercion or fraud is proved
Then chances of probate being granted are very high, even if sisters object.
Objection alone does not defeat probate — proof does.
Final legal position summarised for you:
• There is no 2026 law mandating sisters’ NOC in Mumbai
• Probate is still compulsory for Mumbai property under a Will
• Mother’s self-acquired flat cannot be claimed by her sisters
• Father can lawfully exclude daughters from self-acquired assets via Will
• Daughters’ rights arise only in ancestral HUF property, not self-acquired estate
• Probate is the cleanest and safest route to permanently shut all future claims
If you want, I can also guide you on:
• how to deal with Sub-Registrar NOC demands legally
• how to pre-empt frivolous objections by sisters
• whether a succession certificate is needed for financial assets
• how to structure documents so banks and registrars don’t delay transfers