"unfortunate death of wife" and circumstances for her death is important in the case. This is for women safety.
304B is for Dowry death.— . You already agreed taking Dowry. Taking dowry itself offence ( crime).
Does this incident happened with in 7 years of your marriage?
what happend before her death? is there any case filed against you? Without this, it is very tough to guide you.
I am a Law students.