Follow the below steps to Enable/ Disable languages in CRM Online,

Step 1: Goto Dynamics 365 -> Settings -> Administration. Click on Languages.

Step 2: Select the required Language to Enable/ Disable and Apply.

In this Example, I am going to Enable Language Hindi (India).

Step 3: Click on Ok to Confirm Language Change.

Step 4: It will take some time to Enable/ Disable Languages.

Step 5: Click on Personal Settings to see the Enable/ Disable Language changes.

Step 6: Go to Languages Tab and see the newly added language. Select Hindi (India) to see the changes in CRM and click on OK.

Step 7: You can see the new language in CRM.

Hope you learned a new thing today :):):)