i passed class 12 in 2018 and given improvement in 2019 can i give jee advanced in 2020 and get admission in IIT college if i get good marks??? is their any way?

Hello student I'm sorry to inform you but candidates can appear in Jee advance only two consecutive year one in which they appeared for class 12 and another in next year. So you can't appear in Jee advance 2020 but you can appear in Jee main 2020.
Eligibility - candidates must passed or appearing class 12 with physics chemistry and mathematics with minimum 75 percent marks aggregate from a recognized board.
But if your board result declared in the month of June academic year then you're eligible.
For more updates refer to the link mentioned below
https://engineering.careers360.com/articles/jee-advanced-eligibility-criteria

Feel free to comment if you have any doubt
Good luck