Nonimmigrant visa number

[Vidya_109]

Hi - In the I-485 application form, they're asking for a non-immigrant visa number. My mother has an Indian passport. There are 2 numbers there - one is called Control Number and the other is printed in red and both these are on her visa. Which one is it? I assume it is not her arrival/departure record number on I-94.

Thanks,

Vidya