Legal heir certificate

good noon sir, i am karthikeya. i need an educational for my abroad studies. loan collateral is my family property which is in the name of my mother. the property registered / bought in the year 1992. now 23 years are gone. we have everything including, patta 1992- 2015., nil - encumbrances for 110 years 1905-2015 in my legal opinion position, the lawyer of bank asking LEGAL HEIR CERTIFICATE OF THE SELLER to prove that the seller is only a legal heir for that property. i dont have the current location fo the seller and i dont know he is dead or alive and i dont know about his relatives. Regarding that , i have discussed with one of the lawyer. he said that no need of LEGAL HEIR CERTIFICATE because 23 years are gone. so as per the PROPERTY LIMITATION ACT you dont need to submit that.panel lawyer doing some purposeful indirect activity to refuse your loan. I conveyed the statement to bank panel lawer and showed the property limitation act. but he was so adament with legal heir certificate.i couldn't convince him. so i have approached taluk office. the tahsildar said that if u have patta, nil encumbrance till this year perfectly then you dont need it. and the another factor is you cannot get apply for legal heir certificate. because you dont have any relation to the seller. by the purposful activity of the panel lawyer, i need to get legal heir certificate copy of the seller. is there chance, way or place to get legal heir certificate of seller???.