Counsel for NRI friend

My friend is staying abroad and is a citizen of a foreign country. I know his family in and out since we are best friends. Parents are respectable members of society. He married an Indian girl and made the condition clear before finalizing the marriage that the she will have to move out of India after marriage. The family and girl initially agreed and marriage happened. From the day they got married my friend's family is under trauma. The girl side started accusing him of NOT ACCEPTING her. The girl initially supported my friend's decision to move out of India to pursue a great career opportunity, despite my friend NOT ACCEPTING her. Also, they say that he left her midway. My friend has made repeated attempts to initiate the VISA process, but she simply does not want to go, reasons ranging from I am not sure, What will i do there, i have my career to look into. My friend told him that there are great career opportunities available abroad, but she simply does not budge. The families have spoken multiple times and girl's side agrees that they will fully cooperate, but they turn around to same points again. This is very grueling for both boy and his family. Girl says to my friend's parents that I will go surely and she has understood now that my friend is a very nice person, but her parents have a different story. They have come to know that girl's family is planning to file a case. Boy's family has witnesses to testify that girl tells lies. Although there are no grounds for the charges made by them, please advice how should boy's family proceed. Should they wait for the case to happen or can they take some action to protect themselves anyways. Please answer specifically: - What proofs will work - Whose testimony will be valid for boy's side - Will my friend face arrest on arrival on India - What action can be taken to protect ourselves. - Can they file a case of mental harassment of not being with my friend before girl's side does that. Would that make any benefits.