mother gifted her plot to her son.  Son again excuted a gift deed in favour of his mother after 6 months of the same plot. Now mother want to take loan on it from bank.

The bank official objected the title deed i.e. gift deed and not will to provid loan. Pl tell me why the bank denied the loan on the said plot? 

is there any legal problem?

please give detail answer.

He can keep the link documents and release the loan.  However the title of mother to be ascertained, may be he found some defect in it.  That may be an ancestral property and her share may come in dispute.  Another reason could be doubt.  Why she gifted to son, if she wanted to take it back after six months?  Bankers have no time to clarify their doubts. So rejected loan.