Why would indians still ask people what caste they belong to

Well... the caste system is something that cannot be changed when the person is being born in the place. If your parent are from the Vaisyas of the caste system, you will also and if do something bad and it's like a crime you go lower but you can never go up on the caste system. People say there are only 4 stages of the caste system, but there is one more which is the " untouchables ".  This was named because they do work that Indians hate to do like clean toilets in public restroom for example. Hope this helped!! >.<