Hello im kinda new to this speedrunning thing and i wanna ask what RTA time is?

RTA = Real Time Attack. It is a timing method that means a run is timed with “real time” starting with the first input (as defined by the game’s community/LBs/rules) and ends at the final input/loss of character control. Real time means that once you start the timer, you can’t stop it until the run finishes or you are forfeiting it and quitting/resetting. The timer will continue even if you’re not playing because you need say stop and eat.

This is in contrast to a game that is timed using In Game Time (IGT) where the game itself times the run and reports it at the completion of the game. In this case, actions like pausing or cutscenes/loading might not count towards the final time. There’s also Segmented Runs which allow you to complete a run in segments (usually based around save points) so you can individually optimize each segment.

Can i use the stream time AS a timer? Cause im using PS4 only :/ and cant have a timer

A time and a stream are not related. You can stream without a timer. All that matters is that you have an accurate time at the end of the run. A stream timer is not an accurate timer and shouldn’t be used. Feel free to use any of the regular timers on your computer (LiveSplit, WSplit, etc) or even an app on your phone, whatever works best for you.