I got a new rifle so orderd dies got bullets powder and primers. One hic up only received one die so far sizing., so here going the question can i use similar size seating die till real one comes
Depends on the type of seating die. Hornady for example you could use another 6mm seater on your 243 or 6 creed because the body is not caliber specific. Some companies have seating dies that are cut like a chamber to support the case during seating.
I wouldn't be surprised if most had the cheapest set they could find. I mostly use Hornady and RCBS. I buy the Hornady split lock rings to put on my RCBS dies.