1. A adoptive child cannot claim interest on the "Ancestral Property" of his adopted parents, IF there are other original "natural" line-of-the-tree claimants available.
2. A adoptive child does not have "ancestors". By law a adoptive child is a "legal heir" BUT NOT A "NATURAL HEIR". BUT not for purposes of "ancestral property", by the logic in point no. 1.
3. If "orginal or natural" line-of-the-tree claimants are not available, then the ancestral property is transferred to the property as if self-acquired by the adopted parents. AND whatever is left by the deceased adopted parents is automatically succeded by his adopted son and not otherwise.
This can be disputed and twisted in several ways, if need arises.
Keep Smiling .... Hemant Agarwal