Primary address or the secondary address on invoice ?

No need any Confusion about the billing Address...

If you want received the supplies to Your Primary address then You will instruct to the supplier... Also the same way to receiving supplies to your Secondary Address...

But, Condition only Condition both Address is added in Your Registration...

So if i have to receive material in my secondary address, the main buyer address in the bill should be my secondary address ? and not my primary address ? did i understand it right ?

Yeah...

You are exactly right... But, The Add.Place is in GSTIN portal... It mean the place is in Your GST registration details is must...

YES THAT SECONDARY PLACE WAS ADDED AS MY ADDITIONAL PLACE OF BUSINESS IN GST

Then no need to worry about supples received in Add.Place

but the bill should mention the dellivery address... otherwise On the way it can be impounded 

Can't understand...!!!

i mean since the material is to delivered to my secondary address, the bill should mentioin my secondary address only. otherwise it may get impounded..

Yes... May Be...