When using a conditional branch, with a script call:
$game_variables[2] == 1 || $game_variables[2] == 6 || $game_variables[2] == 10 (And so on)
The '||' means 'or' in the programming world. However in the case of Ruby/RGSS you can simply say 'or'.
So this would work also:
$game_variables[2] == 1 or $game_variables[2] == 6 or $game_variables[2] == 10 (And so on)
Be wary though. Because The following would crash your game:
$game_variables[2] == 1 or $game_variables[2] == 6 or $game_variables[2] == 10 or
You've set no 'or' condition after the last one. So if you have that command there, your game will blow up and your CPU will hate you!
A nicer (and more clean looking) way however, might be to use the following in that script call instead:
[1, 6, 10].any? { |i| $game_variables[2] == i }
Where '[1, 6, 10]' would be the numbers you are looking for, and are each separated by a comma.
For Example: '[1, 4, 7, 12, 18]' would check the variable against those numbers to see if 'any?' of them matched up.