Your son's growth is within normal range but I understand your concern and desire to have a good final height for your son.
You are doing an excellent job in ensuring regular physical activity and optimal nutrition.
Next Steps
Despite his outdoor play and fitness
vitamin D levels can be potentially low in Indians. So my only suggestion is to get vit d level test done. And just in case levels are below 30 vitamin d supplementation can be done. it is totally safe with no chance of vit d toxicity in recommended doses
Health Tips
I stressed on
vitamin d since fixing it would lead to final height in your son. you can't fight the genes he ll probably not be six feet tall since both parents aren't that tall. but he ll definitely reach the maximum of potential height. hope this helps. thanks a lot.