Report said "minimal fluid collection noted in both tv sacs for hydrocele?" what to do so that the fluid will not get increase? any precautions?

Not a very: Impressive ultrasound report. I wouldn't be worried by it. There is not a great deal to do to avoid hydroceles except avoid testicular trauma. Most just resolve over time. If you are still that worried speak to a urologist.

No,...: Some fluid inside the space of tunica vaginalis of scrotum is normal to serve lubrication between testes and scrotal wall. "minimal" fluid may not be clinically significant, but just a report from ultrasound reader's subjective interpretation. Medically, there is no known method around to prevent fluid collection if it is going to happen. So, ask doc timely; time will tell.