As per the official website of IIT JAM 2022, there are no upper age limit/maximum gap year mentioned. Thus, if you wish to go for the IIT JAM 2023 after the 6 year gap then there is no problem and you can appear for the examination undoubtedly. The papers available in the IIT JAM examination are-

• BIOTECHNOLOGY
• PHYSICS
• CHEMISTRY
• ECONOMICS
• GEOLOGY
• MATHEMATICS
• MATHEMATICAL STATISTICS

For the IIT JAM 2022 official website consider the link below:

https://jam.iitr.ac.in/minimum-educational-qualifications.html

For more information regarding IIT JAM 2023 consider the link below:

https://university.careers360.com/exams/jam

I hope this helps. Wish you a great day!