Why project ask for previous 2 years band

I was on bech for 20 days then after allocated in one project But today after 15 days they are asking about my last two years band I said C in previous and B IN CURRENT They said sir is asking then cut the call

Why they asked , what they do with this band . I hear about increment letter will come to this September month so is this related to this one ?

Very disappointing to know some one please help