Which college should I choose having 38 months of work experience in a non-IT field, Great Lakes PGPM or NMIMS Mumbai campus?

You can choose Great Lakes if you would like to switch industries and finish your MBA in one year. If you don't want to change industries and have two years to spare for an MBA, NMIMS is the better option.

The cost is nearly the same, however attending NMIMS takes a year more, so you have to consider the opportunity cost as well.

Regarding exposure and industry interaction, NMIMS is better. You should make a decision keeping in mind all these points and your personal considerations.