your wife has right to get her share in the property jointly named with you. if this property was registered in your name only then she can't claim share in it. The Marriage Laws (Amendment) Bill 2010 is still pending in parliament that will give the wife, in case of divorce, half a share in her husband's residential property, regardless of whether the property was acquired before or during the marriage.
you have paid all emi but it is registered in her name also but she has limited right in this joint property, if you refuse to give she can live in it but she can't sell it. she is ostensible owner but according to benami property act she is deemed to be co-owner of the property so it will be decided by the court after divorce.