Yes Syed, It is possible to apply again after canceling the admission. You have to apply again next year by filling the online application form and verifying the documents again.
I know many students who have canceled their admission after studying for 1 year, and now they are studying again under PMSSS.
But I believe you can only apply next year after that if you will again cancel the admission then I am not sure.
I will also suggest you, try to change the university or the college under the same university if you are finding problems studying in the current college. This is possible If you talk with AICTE and the college and they find your reason valid.
Private colleges don't easily allow you to change college but government colleges give you support in your problems, but you have to talk with AICTE to change the college while continuing your scholarship.
Hope this was helpful, Please share this website with your friends so they can also get help if they are planning to study through PMSSS.