Municipal Corporation Of Delhi (Mcd) — Query related to birth certificate

Dear Sir/Ma'am, I myself Khyati Pahuja born in sonipat having a birth certificate in the name of Chavvi.My name in all the other records is Khyati only.Now as i want to apply for Passport, i need my birth certificate in my name.Please confirm that from where i can get a new certificate in my name.or a declaration on plain paper with my name and details signed by my parents will suffice the purpose. Early response will be highly appreciated.