This offence is called as Bigamy under the provisions of Indian Penal Code, 1860.
She can file criminal case against him for bigamy U/S. 494 of IPC. Punishment is Max imprisonment of 7 years + fine. This offence is compoundable (withdrawn) by wife later on. This can be clubbed with Section 498A also as this is a form of mental cruelty as well.
Since the offence of Second marriage is committed in other Country, it will be advisable that the comlaint is filed in the other country so that he will be tried there and / or deported to India systematically. If you file complaint in India, Police will take there own sweet time to arrest him. It is also legally right if you file complaint in both the Countries. So that police can arrest him the moment he comes to attend any date for divorce matter.
Regards
Pankaj
Disclaimer:
This opinion is genralised and can change after understanding minute details of the case. I dont claim my self to be an expert in the field and hence client is advised to take second opinion before proceeding.