Fake 498a and other charges

Dear Learned counsel, I am a student under course of LLB, I have a friend who has been accused of 498a and other charges. However to state the facts hereto, The wife of my friend already had a kid from another man whom she claims to be in a live in relationship for couple of years and later she married my friend on pretext that she was alone and needed emotional and social security for her and her child. They got married in Arya samaj mandir in 2018 and soon my friend discovered that the wife was of criminal nature and into match fixing, gambling, drinking and drugs etc and due this gambling habit the wife kept on demanding money to pay for her gambling debts etc.My friend within 3-4 months left her, however he suddenly got a call few day back from local p. s that a 498 a was filed and now he is shocked and helpless, he turned to me for suggestions. Meanwhile This wife got married to another guy and borne another child while there are conclusive proof of this marriage and the child too still as per the Indian law u/s494 even if my friend applies for bygamy he is unable to protect himself or his family as cops have been threatening him for arrests and more. my query to all learned counsels are 1. what can be done to annul or declare the marriage null and void. the marriage solemnized in 2018 and they have been seperate within 3-4 months. since then. 2. what should be the course of action for My friend for AB or Regular Bail. 3. what can my friend do to prove this was a honey trapping situation. 4. The wife has past criminal records of prostitution and was in jail for some time but that case was aost 22 years old so how can we pull up a record for that. 5. The wife had in between the live-in with the other guy and marriage with my friend had file a case against some other guy claiming same story of 498 a and other charges, however my friend has no idea which court and what date it was filed or the case no. this was before the marriage with my friend solemnized. so how can we pull up a record for that. I understand these are probably weird situation however all suggestions are more than welcome and also all you leaned counsel would help me as a mentor too. thanks in advance. with warm regards