can my xbox one reputation go down if i get suspended?

Reported feedback by other players.

if you dont mind me asking, what causes the reputation to go down then?

The rep system is separate from suspensions so typically no.

Rep will go down over time.

With unjustified reports my reputation can go down?

If I rack up many reports in a short period of time, will my reputation automatically go down? No, your reputation will not go down until someone from the Xbox Live Policy Enforcement Team reviews the reports. If the reports are false, they will have no
impact on your reputation. If the reports are confirmed, your reputation score

so you got caught breaking the rules .. accept and move on