How can I get a copy of my marriage certificate online in India?

To whom it may concern, I work for Italian Citizenship Assistance. I'm currently helping a client of mine with her Italian citizenship application. Italian authorities require that applicants retrieve fresh certified copies of vital records pertaining to them and their family. I'm hereby contacting you because my client would need to retrieve a fresh certified copy of her mother's marriage certificate, which occurred in Bhavnagar. The certified copy will then need to be legalized with Apostille and translated into Italian. Will you be able to help us? If you will, my client also asked if you can kindly provide us with a timeframe and the fee for your services. Thank you in advance for your assistance. I look forward to hearing from you.