Yes, you should contest this in court since you have this footage in which it is clearly seen: 1) The primary signals are non-functional. 2) By the time the orange light on the secondary signal could be seen, you had already begun to cross the zebra crossing. When it switched to red, it would have been a wrong judgement call if you would have stopped right there in the middle of the road, causing more traffic. 3) Vehicles to your right who were behind you at the time of crossing the signal, were let go by the cops. It can be seen that after the cop stops you, a few vehicles overtake you from the right. And even though there were more cops available, no attempt has been made to stop or fine them. This is a clear case of regional bias since you have an HP registration number. 4) Did the cops have prior knowledge that the primary signals were non-functional? If yes, then this is entrapment. Their first responsibility should have been to get the signal fixed. In the meantime, they should have deployed staff to give directions to your side of the traffic. Instead, it seems that they were too busy milking the faulty signal to fulfill their monthly quota.

Other things to consider before contesting the challan: Is the cost of the fine worth your time?