What is the dipute between you and wife ?? Try to work out solution by discussing issues with marriage counsellor / by involving families.
From the attitude of ur wife it seems u will have much difficulty in peaceful access of your own child. But pls accept the situation....Any force from ur end will provoke ur wife to go legal and file cases on you /family.
Getting custody of child is an legal option, however these cases take years to reach to its end and u will waste many yrs roaming around courts.
As far as possible try to settle dispute outside courts as things have not gone legal yet between both of you.
Take legal steps after carefully assessing the situation . All the Best !!