First you must be clear about requirements (arch, mep etc). Have a clear understanding of dwgs, are the cols masonary, non load bearing? Have you prepared 2, 3 different struc schemes? If you think you can value engineer and reduce cols, check with client req if they too want it.
Then you make sure the scheme is working, deflections, load paths, foundations, framing, cost.
Reducing cols mean, bigger beam and slab spans and so more deflections. Have you checked that? Also more local load on foundations if cols are far, and more sway in wind/eq bcz less bending stiffness of vertical elements (if you are not increasing col/wall sizes to compensate that).
If above is okay, you can eliminate cols that are not required. As a struc engr you have to be proactive, pitchin and promote the "most efficient" scheme that is "simple" and "necessary".