Hello Lavanya,

If you qualified in the JEE mains exam and you are be among the top 250,000 (including all categories) candidates ,then you are eligible to write the JEE advaned exam .And the age limit is not more than 25 years. And maximum of two times in two consecutive years are write the exam.For more details once visit the below link.,

https://engineering.careers360.com/articles/jee-advanced-eligibility-criteria

Hope this helps you...