Under Hindu law, a partition of joint family property has to be done:

Partition of joint family property "Can be oral or in writing"; no particular form is required. If a written instrument itself effects the partition of immovable property, section 17 of the Registration Act requires it to be registered, but a memorandum merely recording a completed oral partition does not, as explained in Roshan Singh v. Zile Singh (1988).

Current law: Vineeta Sharma v. Rakesh Sharma (2020) emphasizes the strict protection in section 6(5) of the Hindu Succession Act: a mere oral-partition assertion cannot defeat a daughter's rights under the 2005 amendment. The usual statutory recognition is a registered partition deed or court decree; exceptionally, an already completed oral partition may be accepted with cogent contemporaneous public documents. This does not create a universal rule that every ordinary partition must now be written.