Nairs are a branch of Nagavanshi Kshatriyas found in the Indian
state of kerala. They are similar to the Bands , Nagavanshi Rajputs
and Jats. Vishwakarmas are supposed to be engaged in the
construction jobs . But, they fall under the Brahmin caste.
Regarding who is upper , the Brahmins or the Kshatriyas is tricky
question . According to the indian constitution no one is upper or
lower , all are equal before law and of course same in the eyes of
God !