Child custody and safety from husband

what is the query

Hi

Happy to help you, but can you please clarify what exactly you wants to know.

Hello, 

If the husband is abusing his wife and child physically, then you need to file an FIR against your sister's husband under section 498A of the IPC and also under section 12 of the Domestic Violence Act, 2005. 
If it's possible, please tell in detail about the case. Your facts are vague.

Regards,

Joy Bose