Son wants divorce against a wife, she threatens to file for harrasment

My son married a girl from Hassan,13 years ago,he was working in a private company at Bangalore,and staying with parents,his wife wants to live separately,so he deside to live,and they lived,so good in a good rented house at Indranagar,he was earning a good pay,they were living in luxury,somebody from wife's family advised to do business,so she forced husband to leave the job to start the business,so he sold his car and bike,had some from parents to start business,and he lost,then wife started to tell her husband to shit to Hassan,he shifted,and with out job my son suffered one and half year, he got a job for a small pay,he managed,to live he has two kids one boy one girl baby,aged 11 and 8,and she wants more luxurious lifestyle,and always quarrel with him,and beats him,because that is her home town .so he got a job at Shimoga, sending most of the money he was earning,our religion is Christian,she all was threatening to make a complaint of harassment,now my son seeks divorce, what to do?