@Ameer
You'll need coordinates because the terrain tag is different for different tiles.
The only thing you can do is load the players coordinates into variables and then check the terrain tag of that position.
And no need for a script - you can do this with pure eventing on a parallel process
1) create an event set to parallel process
2) control variable to get player X position into one variable (done in the game data section)
3) control variable to get player Y position into another variable
4) get location info with the two variables above to load terrain tag into a third variable
5) conditional branch to check the variable with the terrain tag for the number you set, doing whatever you want if the player is on a terrain with that number
6) wait 5 frames (to prevent the parallel process from lagging too much
finished.