Confused between state exam and PhD

I have upcoming state assistant professor exam for which I have cleared SET. And today I have recieved PhD offer letter from IIT Ropar.
As for the state exam I have to study state gk history and other stuff as well along with my subject knowledge (physics). I only have 2 months to prepare for exam and I have to take admission in 7 days.
So I am confused that should I join PhD or prepare for my state exam and then later try for physics. I already took a drop year after my MSc in physics. Please help me.