Hi

In many states OBC category is further divided into sub categories like bc-a  , bc-b etc

So ,yes bc- b comes under obc category at state level.

To know,

Whether you belong to OBC category at Central level or not you need to check the central list the link for the same is provided below:-

If you find your caste in the above central list then you belong to OBC at Central level otherwise you don't.

Another important thing to notedown is   that,

On the basis of caste it is decided that whether you belong to OBC category or not but reservation is there only for obc ncl and not obc creamy layer.

It is decided whether you belong to OBC creamy layer or OBC non creamy layer on the basis of your family income

* OBC  cl i.e obc creamy layer candidates are those whose parents annual income is more than 8 lakhs  per annum and they are not eligible for reservation

* obc ncl i. e Obc non creamy layer are those candidates whose parents annual income is less than 8 lakh per annum and they are eligible for reservation

Thank you