I tried to add 3 forms on my facebook page but it is not allowing me.

I tried to add 3 forms on my facebook page but it is not allowing me. Can i add 3 forms into 1 tab on Facebook or we are allowed to add only 1 form per page?

Using Facebook option from the publish wizard, yes. 

But you may add your custom tabs to your Facebook page and embed the forms using their iFrame code. This guide will help you doing so: https://www.jotform.com/help/82-Adding-a-form-to-Facebook-Custom-iFrame-App- 

I hope this helps.