@ Aashish ,
From what you say, I feel the facts here are incomplete. There are many nitty gritty involved and should be known before deciding what exactly you need to file to give relief to ur client. I strongly feel you need to interrogate your client further and know some more things before taking any concrete decision as to the filing of divorce petition itself as you may need to file something else instead. Bcoz remember, one wrong decision or mistake of an advocate at this juncture will drag the client into endless and futile litigations for years. My advice would be not to rush to file a divorce immediately and consult some senior in your bar with complete facts for the line of interrogation and line of action you need to take in the interest of your client. If it is not possible to obtain guidance then, consult me by email.