How to correct Mother's name on child's birth certificate in Maharashtra?

My Son was born in April 2016 in Thane (Thane municipal corporation) Maharashtra. My name (mother's name) on birth certificate is typed incorrectly. My all documents have name as one before marriage eg P G J (Maiden Name) My Son's birth certificate has my name as name after marriage eg P B P the name which is on none of documents is available. As i dint wanted to change my maiden name. We ignored this. Now we have applied for passports for both of them. I have received passport with my before marriage name.eg P G J (Maiden Name) We mentioned same name in my son's passport application but my son's birth certificate has mother name as after marriage(Again which is none of the documents is available). So my Son's passport application is stuck and objection has been raised by Regional Passport Office. How to get the name corrected on birth certificate?. As we have visited the Birth and Death reporting TMC ward office hence, they say you cannot change anything rite now. We wish to update birth certificate of my son to reflect my name consistent with documents P G J (Maiden Name). and don't want to change my maiden name too. How should i proceed ahead and get it done? kindly guide for the same.