Do I require a separate GSTIN for each state if only purchase & selling but no physical building ?

Hello sabyasachi,

I didn't understand, I am not aware that CGST and SGST have a separate number.

So, are you telling that once I register for GST from Rajasthan (my home town) then I will be getting CGST and SGST numbers and I can use that number for every state and so do not require to register a separate GSTIN for each state? 

or 

you are telling me that for each state I will require SGST number and the CGST number will remain the same so while registering for GST initially I will get GSTIN number, CGST number, and SGST number (for Rajasthan state) and then after depending on the state specific transaction I have to obtain that State-specific SGST number ?

correct me if my understanding is wrong. somebody told me that this State specific GSTIN number expires after 180 days ?