Hello Ravi,

  As per the official rule you can attempt Jee Advance in two consecutive years and there was age limit of 24 years, but for now it has been removed untill further notice. In the qualification section it is mentioned that you have to be appeared and qualified 12th standard exam in 2018 or 2019. So, if you are fitting well for this criteria then hopefully you can write Jee Advance otherwise not. So, in your case you can not apply this year as you have completed your 12th in 2017.

  Good Luck !!!

Hii

No this is not possible. A candidate can appear in JEE Advance exam only in the same year in which he qualifies his class 12th exam.
One can appear in JEE Mains for 3 consecutive years after completing class 12th but not JEE advance.
So if you completed your class 12th in 2019, you can appear in JEE Mains in 2019, 2020 and 2021 but only apear in JEE Advance in 2019 itself not after that.

Hope this helps
Thanks!