The chances are 45% depending upon which stream you choose and what is the seat availability.

If you choose Computer Science then I am afraid that you might not be selected despite of your quota.

If you choose Electronic and Communication then also chances are minimal.There are huge craze for these very streams and hence the competition is tough.

If you choose Electrical Engineering then you have fair chances to get in to Jadavpur but also that to  at 3-4th round of counselling.

All the best!!