How to allow mutiple users to complete the form?

we have single word file need to convert it fillable pdf form and we have many tables in single file.

1) a column should be filled level a and submit 

2) b column should be filled by level b and submit after reviewing a column

and same c is it possible to create form

Unfortunately it is currently not possible to import word document form. The only option is to create your form form scratch in JotForm. Can you please share the word document with us and we will try to help you create similar form. 

On your second question to allow form to be submitted multiple times by different users, yes it is possible to achieve this by taking advantage of our "Conditions" & "Edit Link" feature. I would suggest you to please take a look at the following guide which should help you achieve this:  https://www.jotform.com/help/432-A-General-Approach-on-Building-an-Approval-Process-Workflow 

We will wait for your response.