1. The partition is for the properties left behind by deceased Siva.
Meena being one of the legal heirs and successors in interest to succeed to the estates of the deceased who is reported to have died intestate, is very much entitled to an equal share in the property despite the fact that she received money from her father in the past during his lifetime.
2. If the property sale deed is on the name of Siva then Kartik cannot claim rights over entire property for any reason.
3. If the lenders file a suit for recovery of loan amount then the legal heirs who may inherit the property of the deceased borrower are liable to repay the loan amount in proportion to their inheritance of the property of the deceased.
4. It depends on what case filed against him and what documentary evidences that he relies upon.
In any case in the given situation, his defense appears to be slightly weak.