Is harm ocd related with impulsivity?as i know a person with ocd will not take action .bt can he take a action to harm other if he has impulsivity?

Possibly: OCD is a separate issue from impulsivity but it is always possible that if the two conditions exist comorbidly that the thought of harm could be acted upon. Seek psychological or psychiatric help to manage conditions before regrettable actions are taken.

Abhor & resist? : I recommend reading this great description of harm OCD: http://ocdfreedom.com/harm-ocd-for-limited-release/. Instead of acting w/out thinking, those w/ harm OCD *obsess* over whether they will "lose it" & go on a violent rampage [think Stephen King]. Moreover, they are deeply troubled by these thoughts & abhor them. They also actively resist these thoughts - they don't want to do these things!