Hi, I’m new to Develop Game, I have a problem with a platform, I need to identify when an object is on the platform must be exactly “on the platform”
Sorry for my English
Thanks for the help 
To know when an object is on a platform and to identify which platform exactly, I would use an object variable and I would check collision between object and platform.
Use an object variable for platform and set the value of the variable to 0 when object is not colliding with the platform and set the value of the variable to 1 when object is in collision with the platform. This way you can identify If object variabel of platform = 1, object is on that specified platform.