You can take objection on it.
Nomination is just bank will handover cash and other belonging kept in locker to nominee, but as per law the same should be distributed equally among legal heirs.
So, you give application in the Bank to branch manager that you have the objection and without court order do not give locker and other account handover to nominee behind legal heirs.
Provide legal heirs details to both the bank branch manager and head office too.
I have answered correctly, I knew account holder is dead. Now legal heirs means his (adopted son and wife of deceased) has to take above action.
Only one nominee is dead and other nominee is claiming rights on locker.