I just bought a 1991 jeep wrangler 3 days ago now nd today i drove it on the interstate for 15 miles i was getting off the interstate and it started to smoke wen i got it home i let it kool off nd i opened the radator it was full of water but it was also full of rust would the be the proiblem or maybe something else?

What was the temperature gage reading while the jeep was smoking? Did you check the oil on the dipstick when you shut it off? If so, was the color of the oil normal or was it a grey to white color, indicating water in the oil? Had the jeep been setting up for awhile? What color was the smoke?

Hello,
Are you sure this is rust and not oil? Head gaskets can leak one way or the other or not both. Hoping you did not just buy a vehicle with a head gasket leak. Check your oil level and the color of it. Chocolate milk looking oil is a sure sigh of a one form of a head gasket leak. If your oil is low add some and pay attention to if it gets low for no apparent reason. If you truly just have a bit of rust in your antifreeze then perform, or have an anti freeze flush performed. But this alone will not make it smoke.
Regards, Tony