Does a radiologist perform an operation or he just take x rays and take it to the doctor who does operation?

Not a surgeon!: Some (interventional) radiologists perform procedures. Most do not. However, we also do not take x-rays. We interpret imaging studies (xray, ct, mri, us, etc) to try to give a treating physician a diagnosis.

Radiologist: Generally radiologists interpret exams and diagnose illnesses from many types of radiological exams such as x-ray, ct, MRI and ultrasound to name a few. The findings are passed on and then surgeons will operate. Interventional radiologist preform certain procedures such as placing stents draining abscesses putting in infusion catheters etc....