My mother is 2nd wife of my father. We are 2 sons. 1st wife had 1 son. My mother have property in her name and also we reside is in my mothers name. My father have another property also ( Mumbai and Gujarat). Whether my step brother claim on my mothers property?
What are his rights?
If my mother make will then can he challenge?

Generally a step child has no claim on a step parent's estate unless the step parent adopts the step child. But I'm not familiar with the laws in your country. So I would strongly suggest consulting a local attorney and have your mother make a will. Any will can be challenged, but if prepared by an attorney the challenge is less likely to succeed.

First you did not say where you live.

Also is child adopted ? ( does not sound like it)

The step parent can list the other child in the will, and then they will have a claim. But normally no, a step child has no legal rights to property.

They may try, so you may have to fight it out in court

Fr_Chuck, Mumbai and (I assume) Gujarat are in India, so that is probably where OP is.