In the present scenario you cannot divorce your wife. It is not clear which fact she is trying to conceal. Whether that fact is material to the consent for marriage. Section 12 of the Hindu Marriage Act provides some grounds for nullity of marriage.
Fraud, coercion, concealing material facts relating to the marriage which may affect the consent of the party are few grounds which render the marriage voidable.
If any of these facts is existing in your case then you can file a suit under Section 12 for the nullity of marriage. Your marriage is not consummate yet, hence, you can file the above suit.
You cannot file divorce case within one year of marriage unless any exceptional hardship exists. Your wife is not performing her matrimonial obligation i.e. no sexual intercourse since marriage. However it is a mental cruelty but it does not form an exceptional hardship for you.
You should consult a marriage counsellor or psychiatrist to find out reason behind the sexual indifferences. If it is a mental disease which is incurable then you can annul your marriage. The disease must be incurable and it is also important that she has been ailing from that disease before the marriage.