Once you subscribe (starting at around ₹300/month or less for quarterly plans), every episode has a button right inside the app. You can download multiple episodes in HD (480p, 720p, 1080p) and watch them for 30-48 hours offline. No broken files. No malware.
If you're interested in Ullu content, I recommend checking out the Ullu platform directly. They often offer a free trial or subscription-based access to their content. Not only is this the legal way to enjoy their series, but it also ensures you're getting a secure and high-quality viewing experience.