Question 32: In GST, can we use amount of electronic credit ledger for payment of GST irrespective to any correlation between input tax credit and GST payable of business verticals to another business vertical of a GSTIN.
2. in 
case of import under exemption notification, can we claim part exemption and pay 
for rest and take credit of duty paid in GST.
Answer:
There is no one to one co relation of credit on  
inward  and outward supply It means  if you have one beauty parlour ,one show 
room and one factory then ITC of all the inwards can be used to  pay tax on all 
the out wards supply. 
But the only point is 
that the credit will flow    with in  the same registration so if have taken 
different registration for different verticals then it will not apply
Please mention the notification you are talking about and the exemption you want to avail because in some cases the answer may change. (Reply dt. 19/12/2017)