See there are many aspects that come into play when we talk about various colleges.
Many colleges that take admission for 70-80 percentile have decent enough placement becasue of the following causes:
1. Diversity
2. Alumni Network
3. Accessibility
4. Age of Institution
5. Conection of the Facult and the Administration

This helps a lot in clearing any coinfusion about the colleges. It would be better that you make a list of the colleges that you have in sight and then either talk to their alumni or the current students to take an informed decision.

Hi Ravi, I would recommend you to attempt CAT again and improvise yourself with proper self-evaluation which will result in better results and apply for Tier 1 colleges only. Because, the number of MBA grads passing out each year is too high and in such a competitive environment, your B school plays an important role. Also, the facilities provided in tier 2 & lower colleges are not conducive for your personal development. The ROI is also very poor.

So, I would recommend you to take up a job while preparation which will add to your work exp profile and help you get some points that will help you in getting admission in a good college as well.

All the best.

No they ar enot worth as cutoff already indicates demand is lower. Colleges in top30 List shall always have cutoff abov e90 percentile which should clearly indicate good demand and brand recognition of colkege. 

Only few colkeges like Welingkars Munbai where cutiff drops beloe 80 percentile is recommended beacus eof its brand reputation and rankings and placements scenario.