Can someone tell me if pronamel toothpaste good to re harden the enamel ?

Yes but...: Yes, but it hardens enamel on a "molecular" level it will not visibly restore missing enamel.

Proenamel is: A good toothpaste. There are other toothpastes like mi paste available through your dentist which are also very effective, but considerably more expensive. Hope this helps.

Depends: For minimal decalcification pronamel or mi paste can be helpful. For moderate to severe decalcification restorations will probably be the best option. Have your dentist examine you and make recommendations.