• Yes, if your state is other than West Bengal u are eligible for WBjee exam, because WBjee does not require domicile of West Bengal.
• Also as Jadavpur university does not require domicile of West Bengal so you are also eligible for taking admission in Jadavpur University.
• You will have to score better to take admission in jadavpur university as it is the top university of wbjee.
• For JU CSE, you require a rank of under 150 (to be safe).

All the very best and good luck.

Yes you can. See the domicile restrictions are only for Govt colleges and not the universities. You could apply to any university and get a seat as they are open to other state students. Also the entry will be through WBJEE. The university has just not specified the quota for other state students. SO I dont know where you have this information of 15% quota from. However reserved candidates will not be able to get any reservations unless they belong to WB.