Hi,

I have recessed led lights that are controlled by 6 different switches.

I opened them all up and 5 are 4 - way and one is 3-way.

If I install the 3-way dimmer at the 3 way switch - will it work? It's just that I did not want the switch to have the dimmer as it is not conveniently placed. I wanted one of the 4-way switches to be replaced with a dimmer

 

Yes! A 3-way dimmer will replace a 3-way switch.
(assuming it's rated for LEDs and such)

Replacing a 4-way switch with a dimmer gets a lot more complicated and usually requires smart switches. I'm not aware of a non-smart-switch solution for that. (But I realize that's not what you're asking)

 

All X-way circuits start with 2) three way switches and the rest are four way.
You should have two 3w switches and four 4w switches.

A standard 3w dimmer can not go in a 4w location.

 

I tried again and they are all 4 way except the last one which is 3 way

I went to go replace the dimmer at the 3way outlet but have two hot wires and one travel and one ground.

red and black wire with blue tape is hot while the other black is not hot as seen in the pic below

 

How are you measuring for power ?
You should be using a meter or two wire/probe voltage checker..... not a non contact tester.
A non contact tester shows dangerous power in the area. It may show two wires in the same cable as hot yet only one is.

I added an arrow to your picture. The red and black wire that go in that cable are the travelers.
The remaining black wire is common.

Typically you will find the hot/line at one end and the light/load at the other end.
If the red and black wires that are in the common cable are the hot wires..... that would mean the hot is at the other end of the switches. This picture would be the light/load location.

 

I don't know how to check with multimeter but I think this is load /light location as the red/black traveling together are both hot ....

will try to look up some instructions on using multimeter

also can I put a dimmer at this location if it's the load/light - or does it need to be at the hot end.

 

Yes, dimmer can be at any 3-way location.