Hi dipaldesai,
Thank you for using the Apple Support Communities! I understand you lost data from Notes on your MacBook Air and you're seeking a means to recover them. I can share information to help answer this.
Recovery of Notes will depend on where you had your notes saved/synced, i.e. iCloud, third-party account, or local on your Mac. Please see the information below for more details on each option.
-If your notes were being synced with iCloud, you may be able to recover notes that were deleted in the past 30 days, from the iCloud website following these steps: Delete and recover notes on iCloud.com - Apple Support. Please note, this is available with upgraded notes only.
-If you had your notes saving to a third-party account that was set up on your Mac, i.e. an email account, you would want to check with the third-party provider to see if there are any recovery options through your account.
-If you were saving notes locally to your Mac, but you did not perform a backup, there would not be a way to recover the notes. Please consider backing up your Mac in the future: How to back up your Mac - Official Apple Support.
Best regards.