This is a nuanced and important question in Hindu succession law, and the answer depends significantly on the specific nature and timing of the earlier partition, as well as whether it was a complete or partial partition of the family's coparcenary property. Where a genuine, complete partition of HUF property has already taken place before a son's birth, meaning all coparceners' shares were definitively determined and separated, whether through formal division, a registered partition deed, or a court decree, a son born after this complete partition generally does not automatically acquire a right to reopen and claim a share in the already-divided property, since that property has effectively ceased to be joint family property and become the separate property of each individual coparcener from the time of partition.

However, this general principle carries an important nuance specifically relevant to the father's share — under Hindu law, if the father, after partition, retains his own separated share and doesn't further distribute or dispose of it, this share can, in appropriate circumstances, become the nucleus of a new, smaller HUF between the father and any sons subsequently born to him, since the father's separate share, when combined with the birth of a new son, can potentially revive coparcenary characteristics in that specific portion, depending on how the father has actually dealt with the property since the original partition and whether he has maintained it in a manner consistent with joint family character.

This means a son born after partition may have a claim specifically to his father's post-partition share, treating it as a new, smaller HUF's coparcenary property in which the newly born son acquires rights by birth, even though he has no claim whatsoever to the shares that went to the father's brothers or other family members in the original partition, since those separated shares became those individuals' independent separate property, entirely disconnected from any coparcenary relationship with the later-born son. This distinction between the father's retained share potentially reviving coparcenary status versus other family members' shares remaining permanently separated is crucial to correctly understanding a post-partition son's actual rights.

Where a partition was only partial — covering some family assets but not others, or covering the family's interest in some properties while specific assets remained undivided — a son born after this partial partition may retain rights specifically in whatever HUF property remained undivided and continued to be treated as joint family property, since partial partition doesn't sever coparcenary status regarding assets that were genuinely excluded from the division and continued to be held jointly.

Given how these questions require careful examination of the exact nature, scope, and completeness of the earlier partition, along with how the father has subsequently dealt with his own retained share, thorough legal analysis of your specific family history is essential. Reach out via Aapka Legal Advice to assess whether a son born after an earlier Mumbai family partition retains any claim to specific property. The Top Property Lawyers in Mumbai team has successfully navigated complex post-partition coparcenary claims before Mumbai's civil courts, supported by a panel of retired judges experienced in Hindu succession law and criminal lawyers for related family disputes. If you're assessing whether a son born after your Mumbai family's partition has rights to specific property, carefully examining whether the partition was complete or partial, and how the father's own share has since been treated, is the essential starting point for your analysis.