How can I challenge a Will in the Court?

My mother when she was healthy made property in my name in 2010. But I found that my elder brother has made another property will without informing my mother. My mother name in property will was Suman Shinde. But as per family pension record and new photo identity proof the name is Lax I. Death certificate has also the same name Lax I. Please suggest me the right way because he did not look after my mother when she was suffered by cancer. Please guide me. Thanks