No quick answer to that, different species spawn at different times when conditions are suitable (mainly water temperature). Not all of any given species may be involved in spawning at a certain time and some may well be feeding, species such as carp may spawn more than once in a season. Obviously, for many reasons, it's not advisable to try to target spawning fish - much better to go for one of the species that has already spawned or fish not involved in spawning (the spawning activity will be in the margins).
Jerry