Yes, you can definitely appear for the UPSC CSE Examination having passed 10th/12th in Open School and pursuing Graduatiin in IGNOU. Of course once you graduate you may appear for UPSC as they need Graduation as one of the eligibility criteria. Yeah, and I believe youre referring to UPSC CSE.

For more information about UPSC CSE do follow the link below

https://competition.careers360.com/exams/upsc-civil-services-exam