you won't easily get that kind of packet capture for free under windows, use wirehshark on linux on a laptop (boot from USB rather than installing it on the laptop), or, use a mac.
You can also consider to use an AP as a packet sniffer and send the resulting stream to a any machine running wireshark (windows or otherwise), this procedure will be floating around in the forum and will work well enough to show radio headers.
Failing that, you can infer the QAM rates being used, to some extent, by looking into the tx/rx rates being used by the client and referring to the "ht or vht rate table" for the bssid.
This approach is not perfect because some rates are the same despite being different MCS and #ss, but it's about as close as you can get using the controller only, but it's good enough to tell you something about expected throughput.
relevant commands for the controller (you can find a MCS to #QAM X/Y chart online in various places)
show ap ht-rates <bssid>
show ap vht-rates <bssid>
show ap debug client-stats <mac> | include Mbps
show ap debug radio-stats radio X ap-name Y | include Mbps
clear ap debug client-stats <mac>
clear ap debug radio-stats radio X ap-name Y
* where radio 0 is 5 GHz, radio 1 is 2.4 GHz
* use the clear to reset the stats, unused rates don't get displayed, ergo you can run a test and then check the "histogram" that was used.
* beware SM MIMO Powersave which can cause some clients to turn off a radio and thus spray unexpected rates into the histogram, samsung phones especially
hth.