Once a upload is complete , the link should be disabled

Hi All, I hope everyone is doing well.

I have 2 records - 1) Employee's Details   2) Task   3) Upload.

When i raise a request and submit , the details get save in Employee record . and a task is created . For the employee's  they upload few documents like 1) kyc, 2) pan, 3) aadhaar. They have an option to select the document they are  going to upload.

The catch here is for all employees all the uploads are not mandatory , they can upload any 2 or 1 or all three of them. 

Here in the grid , we gave a start link so that the process model of upload document starts automatically and based on the document upload for a request the link should be disabled , so that for same request id we cannot upload any other extra document.

Can anyone please help me with the right approach.

Thank you in advance.