The mutual consent divorce decree cannot be challenged as it is obtained from consent of both parties it can be only challenged on ground the consent was not free and was under some coercion.
Even if you had not given up your complete right over your child than the claim visitation right as you are a parent and have equal right for your child
you can mutually also decide visitation rights with your wife for can file an application for visitation rights in court the court shall grant order on that and provide you with the visitation rights. it is better if you mutually with your wife decide the visitation schedule it will easy for you to get the visitation right.
if it is not decided mutually than you can file an application under secrtion 26 Hindu marriage act for modification of child custody orders.
You can apply under 26 Custody of children. In any proceeding under this Act, the court may, from time to time, pass such interim orders and make such provisions in the decree as it may deem just and proper with respect to the custody, maintenance and education of minor children, consistently with their wishes, wherever possible, and may, after the decree, upon application by petition for the purpose, make from time to time, all such orders and provisions with respect to the custody, maintenance and education of such children as might have been made by such decree or interim orders in case the proceeding for obtaining such decree were still pending, and the court may also from time to time revoke, suspend or vary any such orders and provisions previously made: 58 [Provided that the application with respect to the maintenance and education of the minor children, pending the proceeding for obtaining such decree, shall, as far as possible, be disposed of within sixty days from the date of service of notice on the respondent.]