Hi,
Quick question.

The super channel in wireless in mikrotik devices, it shows 27xx mhz (in case of 2g band) is this really 2.7ghz frequency?
And
same in the case of 5ghz frequency, it shows 6ghz, is it really 6 ghz or just something that I cannot understand

Yes, the wifi radio chipset usually supports much wider range of frequencies and can work outside of standard wifi bands.
But note that rest of the receive/transmit path may not be optimized for these frequencies, so actual tx power and receive sensitivity may vary greatly...
Also it should be clear that you need a license to transmit outside of public WIFI band frequencies.

Many thanks for the reply.
Yes I understand that I need a license for that; so that is why I will be testing it and will be working in a small factory where cable laying is not possible - make ptp links of devices and provide 2.4ghz to users for wifi. lets see how the results come out. factory has steel walls, so signals wont be going out much, and if they do, the area is empty so no one will be disturbed.

Yes, also the other device must support the same frequency, and the antenna must be able to work. For example, some MikroTik CPE devices support 2.7GHz in the chipset, but antenna gain will be 30% of normal, if you use such frequency, so distance will be much smaller than maximum possible. You can see it here on page 3, see how antenna gain drops sharply at some frequencies:

https://i.mt.lv/cdn/rb_files/LHG-170927115805.pdf

Yes, also the other device must support the same frequency, and the antenna must be able to work. For example, some MikroTik CPE devices support 2.7GHz in the chipset, but antenna gain will be 30% of normal, if you use such frequency, so distance will be much smaller than maximum possible. You can see it here on page 3, see how antenna gain drops sharply at some frequencies:

https://i.mt.lv/cdn/rb_files/LHG-170927115805.pdf

Well that is a very valuable information. Thanks for pointing this out. I was planning of something to make a permanent deployment, which, now I should think again.

Anyway, for this particular scenario, it the normal achievable distance on the device you mentioned is 12 KM (i am assuming that) than I dont think that I will have any issue with 1 KM (or less) with 6ghz.

Please do correct me if I am wrong