Policy to Block Uploading the Pdf file to Web. You may use any file extentsion for that select the file extension.
Login into DLP console.
Configuration needs to be added. For that go to System --> Agents ---> Agent Configuration
Click on the Add Configuration.
Select the Monitoring, Here we have enabled the HTTPS and HTTP.
Once created it shows in the below information. Click on Apply configuration.
Apply the configuration to the server. From the drop down select the newly created Block Upload and highlight the Server to be the applied and click on Apply and update button.
Once applied the server and related configuration will be shown in-front of it.
Create a response rule which should prevent (Block ) the upload. Click on Manage à Response Rules
Click on Add Response rule button.
Automated Response will be created. Select the radio Button for Autmated response and click on Next
Select the action that is required, in this case, Prevent: Block. Once selected click on Add Action Button.
Make changes to the Notification Content. Here the default Value is set. Click on save Button.
Now turn to create a Policy. Click on Manage ---> Policy List
Click on Add Policy
Click on Next and here a Blank Policy has been selected. 
Click on Add Rule Button after providing the name and description.
The intention is to select the File Type Match, refer the screen shot for the selection.This will be applicable for endpoint , Network & Storage. Click Next.
Provide the description and name and also select the file type. You can select any of the files, for this example PDF has been selected. Once finalized, click on OK button.
Policy configuration is done, now response for the policy needs to be added. Click on Response Tab and add the response rule that was created. Click on the Add Response Rule button.
From the drop down select the rule and Add the response rule. This makes policy created and response for the policy.
Agents have taken the policy and attempt to upload the pdf file to fileshare account fails while other file is success.
Hope this is usefiul information.