The GPA holder can do all such things as are authrozied in or by the GPA. If the GPA says that he can mortgage and/or raise loans against the property, then can raise loans against the property.
If the GPA says that the attornery holder can take loans agains the net worth of the executor, then the the attorney holder can take loans in such a manner so as to peresonally bind the exeuctor for the loans taken by him.
Should the GPA holder default in repayment of the EMIs the bank is legally empowered to proceed against the property.
The bank may or may not proceed against the GPA holder depending upon whether there was any personal guarantee by the GPA holder or not.
The bank would proceed against the GPA executor only if there was such a convenant in the GPA so as to personally bind the the executor, but not otherwise.
Having said all the above, it is necessary to examine the GPA and also the loan sanction documents before any opinion can be expressed.