I have taken a housing loan in joint account with my mom, The bank is asking for power of attorney from me to disburse the final cheque.
You just have to draft a Power of Attorney letter and noterize it. For this you have to contact some local lawyers. If you want to know about them, ask me.
Actually the bank should have informed you as to how you should go about this. I suggest you give them a call, I'm sure there explanation will be better than mine. Besides they know exactly what they want.