Got answer of my question on OnePlus2 Forum. Sharing the same here to help other users.
To solve this we need to run a script on Mac or Linux based system.
- Enable debugging mode on your OP2 (OnePlus2)
- Connect to your Mac or linux based PC
- You will see a drive on your finder with the name "One Plus Drivers"
- There you will see one file with the name "Op2_adb_config_Linux_OSX.sh"
- Copy this file to your documents folder
- Open terminal and execute the above file (sh Op2_adb_config_Linux_OSX.sh)
- It will perform necessary steps on your system and then your OP2 will be recognised by Android Studio.