Gujarat Co-operative Societies Act, 1961
(1) Where a mortgage (other than mortgage to which sub-section (2) applies) executed in favour of a [land development bank] either before or after the commencement of this Act, is called in question on the ground that it was executed by the manager of a joint Hindu family for a purpose not binding on the members thereof whether such members have attained majority or not the burden of proving the same shall, notwithstanding any law to the contrary, lie on the party raising it.