After marriage change of surname and middlename of wife

Dear Lawyersclubindia family members, Greetings to all of you. I have some queries: My arranged marriage has held in Feb., 2015. My surname and my wife's surname and middle name are different. Please let me know that is there any provision of law that for wife there is automatic adoption of husband's surname or not? We are hindus and marriage was arranged. We have not yet tried for marriage certificate. In marriage certificate which surname of wife will prevail? My wife is interested to adopt my surname. Kindly let me know the way that my wife's surname can be changed legally so that in future no mismatch and complexity will remain. She is also applying for further study and various government sector jobs, so which surname she should write in forms? Thanks a lot