Hello Sankalan,

Your rank in WBJEE is quite well. Considering the last year's cutoff there is tough chance for you to get admission in Jadavpur University, Kolkata in mechanical engineering as the closing rank last year was 771. But there are many other branches you can easily get admission in that are Instrumentation and Electronics Engineering, Civil Engineering and chemical engineering 

Good Luck! 

Sorry dear, it not possible that you will get mechanical in this rank, the best branch you can expect is Metallurgical Engineering in Jadavpur.