My wife always threating of women cell

Brother spend one more year peacefully and she would not be aligible to file 498a or dowry case.

Reply to your question --- gather video and audio evidence and be happy. file a case in court and get divorced by showing video and audio evidences.

File divorce case and seek custody of baby with the advise of local lawyer

File a divorce petition on the grounds of adultery, cruelty and non consummation of conjugal happiness.  In a vengeance, she may file 498a and DV Case and Dowry cases.  Do not worry, you can defend the same by engaging an experienced lawyer.  As you are innocent you will come out of the cases.  Meanwhile collect photos, videos, audios of your wife when she engaged with his paramour. Also take audio and video when she is quarreling with you and collect some friends, neighbors who can come to court and give evidence in your favour.  If you want further clarification on this aspect contact me ravinder2345@gmail.com, I will give you elaborate opinion.

Behave with her friendly , take care as a loving husband, tell her that she is the mother of a baby  and as such she must refrain from doing anything that may spoil the life of her baby.. Try to find out your fault or unnatural activities that might have caused hatred to you and lead her to  follow such unnatural behavior after six years of married life.  For threatening you can lodge a written complaint in the local police station for future reference...

There must be some strong reason for a change in her activities, i.e., adulterous life.  As advised by experts above, find out the reason for this, have an introspection of yourself, analyze the situation properly, take the advise of elders and close friends on this issue.  If the unanimous decision is to throw her away from your life, consult a local lawyer and take his advise for divorcing her.

Adultery is cheating, trust broken is hard to be regained.

Suggest file for divorce after collecting evidence.

There is a diffirence between 304B, which states about Dowry Death and 498-a which is for dowry harassment.

304B can be filed only if there is a death. Which is applicable within seven years.

498-a can be filed at any time during the subsistance of a vaild marriage.

Same is the case with DV