Acts 23:6 (New International Version)
6 Then Paul, knowing that some of them were Sadducees and the others Pharisees, called out in the Sanhedrin, "My brothers, I am a Pharisee, the son of a Pharisee. I stand on trial because of my hope in the resurrection of the dead."
Acts 22:28
Then the commander said, "I had to pay a big price for my citizenship." "But I was born a citizen," Paul replied.
Acts 16:37
But Paul said to the officers: "They beat us publicly without a trial, even though we are Roman citizens, and threw us into prison. And now do they want to get rid of us quietly? No! Let them come themselves and escort us out."
The bible shows paul was a trained pharasee under a famous teacher also his dad was one too but Paul was also born a Roman citizen which means his dad will have done something to attain roman citizenship which is then passed onto the children. In the scripture above the commander talks of having bought his citizenship. In those times there were a few ways to get the desired Roman citizenship not least of which is buying it with anough money but the scriptures do not mention how Pauls dad acquired it.
Jewish tradition talks of Paul being a tentmaker before he studied to be a rabbi pharasee.
Reniaa