As we discussed this morning, if it's a well immunized dog, you don't need to vaccinate your son. If not you need to get an Anti-rabies vaccine to your son.
Cost is somewhere about 320-370 rupees.
Next Steps
You can Consult a physician/pediatrician in your town for further treatment.
Health Tips
1. Wash the area of bite thoroughly
2. Apply Antiseptic cream twice daily.
3. consult pediatrician for pain killers and vaccination.