You can appear As many times as you wish. It doesn't have any restrictions like JEE Mains.

 A candidate appearing in 10+2 exam in 2018 may sit in the WBJEE 2018. But they will not be eligible for allotment of the seat for admission if they do not pass the qualifying examination with the required eligibility.

• The lower age limit is 17 years as on December 31, 2018.
• There is no upper age limit to apply for WBJEE 2018.
• But for admission in Marine Engineering Course, the upper age limit is 25 years.