Question on Dowry case, immigration & cheating

My Son is a naturalised US citizen, originally from India. When he was Indian Citizen he got married to an Indian Girl, two years ago. Within 6 months of marriage he became US citizen. He initiated Green Card processing, which normally takes upto 1 year for the girl to enter US. During this time, the girl was working in one of the Gulf countries. In 18 months after marriage, the Green card processing reached the final stage and the boy was supposed to upload some legal documents to US authorities (such as financial support documents & sworn affidavits) After marriage, the girl refused to have sex with him, despite his repeated visits to India/Gulf during these 18 months. Further she had illicit relationships with other guys. Due to this the boy applied for Divorce in USA, being a US citizen. Sensing the Green card processing may be stopped due to this divorce case, the girl made forged documents (financial support documents & sworn affidavits) with the boy's electronic signatures, and uploaded them to the US government site. The moment the boy came to know of this forgery, he notified the US authorities, and suspended the GC processing (which was at it's final stage) Current situation: During the pendency of the Divorce case in USA, the girl filed a police complaint in India accusing the boy and his parents (who are also US citizens) of Dowry Demand. The girl's side demanded Rs. 50 lakhs to withdraw the case, which we refused. So, the complaint is forwarded by the police to the social welfare department of concerned district for further investigation, a month ago. Recently the boy got ex-party Divorce order from USA court. Now US authorities are ready to take up the 'Documents forgery' done by the girl with Indian Authorities. Is there a way to file a forgery case directly with Indian Authorities? Is there a way to file a case against the girl for demanding money to withdraw the 'Dowry Case'? He being US citizen, what is the procedure for filing a police complaint / court case in India? Which city will be his jurisdiction for such cases?