He seems absolutely normal...in both weight and height. Use WHO/ IAP GROWTH charts to trach his height. In First year baby will grow by 25 cm.
At birth length...50 cm,
At 1 year .....75 cm. At 8 months..66 cm...is absolutely fine. You can use Anthrocal application also for growth monitoring.
Next Steps
if still feeling he is not growing can show pediatric Endocrinologist or pediatrician
Health Tips
use Growth charts available in the net freely for Indian children