1. The said Ancestral Property can be safely purchased via a Registered Sale Deed, "COMPULSORILY" signed jointly with mutual consent by "ALL" the residual legal heirs, who should sign as "Confirming & Consenting party" on the Sale Deed. Further each such residual legal heir should also execute a "irrevocable indemnity bond", with strategic clauses indemnifying the buyer party against all losses, legal disputes etc....
2. IF above can be done, THEN there is no need for any additional documents or procedures, whatsoever.
Keep Smiling .... Hemant Agarwal