Hello abhisek,
I will suggest you go for pvt engineering colleges now days the seats are vacant in not so much famous college in your area which are pvt they will give you admission but if you will gor famous college or the college will have some name in academic then you will have to go through management qouta.. but 40% is very low marks to do engineering as you will face many problem related PCM  subject because in 1st sem of engineering the mathematics is 12th based but its much tough if your 12th syllabus is not clear ..
Sorry but i am not here to demotivate you i pray for your bright future
Best of luck for you future
Thank you