The treatment of choice for primary grade V vesicoureteric reflux involving both kidneys in a 6 month old boy is –
Antibiotic prophylaxis
Ureteric reimplantation
Cystoscopy followed by subureteric injection of teflon
Bilateral ureterostomies.
Since the age of the boy is less than 1 year we will try medical management.
See the below given tables from Nelson and the answer will be clear.

Treatment Recommendation for VUR diagnosed following a UTI