Two Business Units - One With GST and another Without

A persons is proprietor for  two business A & B. Turnover of Business A is Rs. 45,00,000/- and hence he has taken GST Registration for the same. But turnover of Business B is only 10,00,000/- which is below the threshold limit for GST.  

Should he, include the Turnover of B also in his GST Returns and pay tax or is it sufficient, if he pays GST on Business A Turnover.

and for Income Tax Purpose, he declares income @ 6% on turnovers of both business A and B.