What happened
Question papers of the PRT exam held on 29 Oct 2017 were leaked amid mass-cheating complaints; Delhi Police registered an FIR the same day and the Lt Governor cancelled the exam on the basis of a police report, directing DSSSB to re-conduct it. Deputy CM separately sought a CBI probe.
What was done
Source
Primary reference The Tribune ↗ https://www.tribuneindia.com/news/archive/delhi/cm-urges-lg-to-cancel-dsssb-papers-hold-exams-again-507254This entry summarises the linked report. Where the summary and the source disagree, the source wins — and please tell us.