Current address proof like Aadhaar card, water bill, electricity bill or telephone bill, voter ID card, proof of gas connection, Income Tax order, spouse passport copy (first and last page including family details), photo passbook of running bank account etc
can be used for change in address of passport
2) open a bank account in new address . Rely upon sale deed to prove you are owner of flat
3) electricity bill can be changed on basis of letter from society giving its NOC