Occupation certificate for independent house

GHMC APPROVED PLAN FOR GROUND PLUS Ist floor .But I constructed ground floor as per approved building plan.Due to financial problem not able to construct the Ist floor .GHMC has mortgaged 36 sq metres of first floor.I am in need of occupation certificate for ground floor and release of mortagage on first floor,since I am not going to construct Ist floor.Occupation Certificate is required by HMWSSB FOR WATER CONNECTION to my ground floor.Please advise how to get Occupation Certificate for ground floor and release mortgage on first floor.