assignement agreement and certified copy

I have signed an assignemnt agreement for an apartment in Bangalore and given 20% advance. The apartment is ready to move in and Registration is due as of now. The seller had a loan with LIC. I am going ahead with some other bank for loan. Now when my bank has sought for a list of originals held with LIC we got to know that LIC has lost his original sale aggreement. LIC is sat=ying they are ready to give declaration that seller has given them original copy and they lost it. They are also giving me certified copy 1)Now if the seller closes the LIC loan and registers the property and then transfer it to me what the legal implications of this? 2) If I persuade my bank to sanction loan on certified copy then what are the legal implication i may have in future? 3) LIC is giving me an option that if I take the loan from them they ll forego the certified copy matter and sanction me loan for now and later I can get it transferred to where ever I want after registration in my name AFter registration in my name whats the value or legal implication of older sale agreement? Kindly help