Welcome back to the NVIDIA developer forums @cshreyastech !
Please be so kind and give us a little bit more detail:
- What Laptop is this exactly?
- What do you mean by “open source package”? Did you use the Open Source kernel modules and built them yourself?
- Which driver versions did you try and how did you install them?
- Lastly please read this pinned topic and attach the mentioned log information if the issue persists.
My very first suggestion to you is to purge all NVIDIA drivers, disable (blacklist) the nouveau driver and re-install the latest certified version from the Ubuntu Software Manager.
Thanks!