Hello, Suprakash, 

You are  not eligible for WBJEE mains 2020. According to NTA, the number of attempts for admission in a particular academic session will be considered as One. However, as per the age, eligiblity criteria for appearing in Mains 2019 will allow a candidate to appear in the entrance exam for three consecutive years.

For more details check the official CAREERS360 website:

https://engineering.careers360.com/articles/jee-main-number-of-attempts

Hope this will help.

Thanks