I have done My JEE Mains in JAN attempt. Now I want to give advance exam. But I don't know anything about advance. Can you help me???

Hello,
To be eligible for JEE Advanced, you must have qualified in JEE mains 2020 in atleast one of the attempts. As you have appeared for JEE Mains January 2020 session, and if you have qualified in it, then you can appear for JEE Advanced 2020. Out of all the students appearing for JEE Mains, the top 2,50,000 JEE Main 2020 qualified students will be eligible for appearing in the JEE Advanced 2020.

JEE Advanced is the exam for admission into the 23 IITs in our country. The eligibility of 75% in class 12 boards has been removed for this year.
Once ths results are out for JEE Advanced are our, the admission abd counseling will be done by JOSAA.
The syllabus for JEE Advanced is quite advanced as compared to JEE Mains and the questions are more critical thinking based
For more details on JEE Advanced please visit this link https://engineering.careers360.com/exams/jee-advanced

You can find the JEE Advanced eligibility criteria here https://engineering.careers360.com/articles/jee-advanced-eligibility-criteria
This year JEE Mains second session will be organised on September 1st to 6th, 2020. And JEE Advanced will be conducted on 27th September 2020.
Hope it helps