Regarding gst registration in two different states

Our partnership firm is already registerd under GST SAC Code - 0440410(works contract) in a state of India (let's say state-1), 
our partnership firm is invoved in works-contract only in the state-1 & nothing else. 

Now, we are planning to start a retail drug-store in an another state of India (let's say state-2), 
our partnership firm will be involved in that drug-store/pharmacy-shop business only in the state-2 & nothing else, not-even works-contract. 

So; 
we guess that, our partnership firm needs a new registration number under GST HSN Code for Drugs & Pharmaceuticals only in state-2 (& we will not have to mention GST SAC Code - 0440410 in state-2). 
and; 
our previous registration of state-1 GST SAC Code - 0440410(works contract) will be left as it is.. (as we are doing "only" works-contract in state-1 so; no changes here for this GST number) 

N.B. - 
1) name, PAN, TAN, of our partnership-firm and partners, will be the same as before. 
2) our partnership-firm deed has a clause of getting involved in other business (if undertaken/decided) from time to time as per all partner's wish. 
3) we will handle the issues related to PCI, Gumasta etc.. in "state-2" that's not our concern right now. 
4) we will have a rented address/location for our partnership firm in "state-2" BUT the address of the partners will be same as before, i.e., old address in "state-1" 

P.S. - 
The reason behined asking this question is to know whether our understanding w.r.t GST registration procedure of our PARTNERSHIP-FIRM in two different state (referred as state-1 & state-2 above) is correct or not ? 
(i.e., previous GST registration in state-1 under SAC Code - 0440410(works contract) left as it is.... as our partnership-firm do "only" works-contract in state-1 & another new GST registration in state-2 under GST HSN Code for Drugs & Pharmaceuticals as our partnership-firm will do "only" retail pharmacy store in state-2 & we will not have to mention SAC Code - 0440410 in state-2... ) 

So; is this concept of our's regarding GST is correct ??
OR; we are missing something ?? 

Any kind of Comment/Suggestion/Gidence will be appreciated. 
THANK-YOU.