Hi Guys,
Up for sale is a 4 in 1 multiprotocol module for FrSky transmitters
brand new un-used
I bought it to troubleshoot a module i'm building but my module worked so i'm selling this.
comes pre-flashed with v1.1.5 firmware
Rs.4500/- free shipping within India

Will this fit radiomaster tx 16s?

I guess, radiomaster tx 16s comes with built in (default) 4 in 1  multiprotocol module...

Yes it does.
My use case is to use the TX16s in trainer mode, so that I can teach my child. I need to fit another multi module and use that as a receiver for signals from a spare Flysky Fs-i6 that I also have.

I am not able to explain this correctly.. see this video for what I am trying to achieve.