Please suggest to approch good entering colleges in Karnataka with JEE 79 percentile

With a JEE Main percentile of 79, you may not qualify for top-tier NITs, but you still have a decent chance to get into some good private engineering colleges in Karnataka through COMEDK or management quota. Institutes like Dayananda Sagar College of Engineering, RV Institute of Technology, New Horizon College of Engineering, BNMIT, and MS Ramaiah Institute of Technology (through higher fee quota) are worth considering. You can also apply for state counselling through KEA (if you're a Karnataka resident) or explore direct admission options if available.