Hi BhartiYashesh,
In going to be honest, your Mac is a mess with the potential malware, corrupt files, low performance, System modifications, and Configuration profiles. Something also might have gone wrong with the Big Sur update.
I believe that you should just erase and reinstall macOS. However, this can only be done if all your files can be backed up to an external hard drive. To backup, "copy and pate" or "drag and drop" files you want to save. Do not use Time Machine. This will just restore issues.
When you are ready to erase and reinstall, follow this guide. This will erase all data not stored elsewhere!
- Verify all your data is backed up to an external hard drive using "copy and pate" or "drag and drop".
- Sign out of your Apple ID in System Preferences > Apple ID/iCloud > Sign Out
- Shut down the Mac.
- Turn on the Mac, and immediately press and hold Option + Command + R until you see a spinning globe.
- Once you are in macOS Recovery, verify you are connected to WiFi in the top right corner.
- Go to Disk Utility.
- Select "View" in the toolbar > "Show All Devices".
- Select your main hard drive. This will either be the top "APPLE SSD...".
- Click Erase, and input the following exactly:
- Name: Macintosh HD
- Format: APFS
- Scheme: GUID Partition Map
- Click Erase
- Quit Disk Utility
- Go to the reinstall macOS app.
- Follow the prompts, and install on Macintosh HD.
- Once done, setup your Mac, again, and once setup, drag and drop or copy your files back to the Mac.
Cheers,
Jack