Does JotForm has a limitation for submissions of forms ?

Each account has certian limitations. Forms themselfs are not limited, but accounts are. Check this link for info on the limits http://www.jotform.com/pricing 

Yes there is, You check our pricing page for more information about submission limit per account type or you can check the summary below.

1. Free - 100/mo Submissions, 10 SSL secure, 10 Receive Payments | 100MB space | 1 Sub-user account

2. Premium - 1,000/mo Submissions & 1,000 SSL secure & 1,000 Receive Payments | 10GB space | 3 Sub-user account

3. Economy - 10,000/mo Submissions & 10,000 SSL secure & 10,000 Receive Payments | 100GB space | 10 Sub-user account

4. Professional - 100,000/mo Submissions & 100,000 SSL secure & 100,000 Receive Payments | 1000GB space | 100 Sub-user account