Thanks for your questions. Please follow this simple steps to master hard reset your KARBONN K9 mobile –

Step 1: Hold down the Power button to switch on your KARBONN K9 mobile.
Step 2: Then Simply dial this following code: *2767*3855#
Step 3: Now will see the information about resetting your phone.
Step 4: If your phone ask for password, press 1122 or 1234. (1122 or 1234 is the default password of KARBONN K9 Mobile)
Step 5: Wait to complete the whole process.
Well done! The hard reset has just been performed.

Click here for details – 

1. KARBONN K9 Hard Reset code and Tracker password Information – https://www.resetcode.org/2018/05/karbonn-k9-hard-reset-code-and-tracker.html
2. KARBONN K9 Mobile Short Codes. –  https://www.resetcode.org/2018/05/karbonn-k9-mobile-short-codes.html