Hello there! 

Greetings! 

Yes , of course you can take admission after improvement exam,  the main purpose of improvement exam is that it allows students to increase their percentage,  so if you manage to score good marks like 75+ % , then it will be good for , you can even get into iit after getting 75 % in improvement exam, once you qualify jee advance etc. So , you don't need to worry you can get admission after improvement exam .

thankyou