Login to self care and on the left side click on your DTH account ID.
Then you'll see 3 tabs. Go-to connections tab. Scroll down to Services. Under Services, you will see SD Top Ups. Expand it and you'll see an option "Add free regional top-ups". Click on it and then select the two top-ups you want and click save. That's it. In 5-10 minutes the free top-ups will start showing up under your package.
If you need to add any more packs, you need to wait till the status of the previous request is complete. You can't add anything till the status shows "Request in progress".