Apartment land coming from Inam abolision, How safe to buy

Hi, We have finalized an apartment in Bangalore, When we went through the history of land. The first document(Oldest document) is a judgement copy from land court for"Inam abolision" of the land and is allotted to parties. Later these parties have sold it to someone and then conversion has happened from agricultural land to industry and then to residential. Builders have all the duplicate certified copies. Except for the first judgement copy, we have got all other documents verified by applying for certified copies in respective department(kandaaya bhavan) When we applied for the duplicate copy of the first document, They searched and have given the endorsement saying "they do not have any documents for the given LRF number". We have again applied for it, as builders have taken the copies last year Can we buy this apartment even if we do not get the documents after searching? Will there be possibility of file getting lost in the department? Will there be possibility the builders have the fake document and there is no original document at all? Kindly advise. Thanks