Hello,
In order to get divorce you need to file a petition in the family court. There is no concept of outside court divorce. The grounds for filing the divorce petition may be cruelty, adultery, desertion etc. Since you don't know the whereabouts of your wife there is no question of filing a mutual divorce petition.
So approach the court by filing an application for divorce under section 13 of the Hindu Marriage Act on the above grounds. The Court will issue notices to your wife at her known address and in case the she doesn't turn up after the service, the court will proceed ex parte. Proceeding ex parte means that the court will continue proceedings without her presence. The same thing which the inspector advised you. Thereafter, the divorce will be finalized.
Regards,
Nishant