Hi
Since the Resale apartment is already mortgaged to HDFC bank, you should
1) First find out how much money the seller needs to pay to HDFC bank to close the loan and for them to close the mortgage and release the title deed.
2) Once you have the amount required to be paid to HDFC bank to close the loan and release of title deed, then you should enter in to an agreement of sale wherein you clearly mention the following:
a) Outstanding loan amount payable to HDFC bank
b) Advance money payable to the present owner
c) Amount payable to HDFC bank for and on behalf of the present owner for closure of loan and release of title deed.
d) Seller's responsibility to obtain No Objection certificate from HDFC bank
e) Timeline for payment of remainder and
f) Time line for registration.
3) Normally when there is pre-existing mortgage, if the seller is unable to close the loan by himself, we advise buyers to pay the Bank (Mortgagor) directly the pending loan amount at the time of seller registering the property in your name.
4) Banks will hand over the title deeds to the seller and you should ensure to collect it from the seller immediately at the time of registration.
5) Normally, DD for closing the loan, Issue of No objection certificate, registration and collection of original title deeds all happen at the same time (at the time of registration) and these needed to be coordinated.
Hope this information is useful