As a Citizen of India, you have to go through legal process of divorce in India, Dubai divorce will help you only but its not legally valid. same apply to custody and maintenance too.
if you are india, and if they come to india, you can get order to stop her from leaving India with your son.
if she never stayed with your family then you can go for remove your mother name form the case.
in 498A case if she said they gave you dowry then your can counter, sue her dor DP3 also.