Is Fs-i6x or Fs-i6s good buy as transmitters ? Which one is better
I personally haven't used either of the two radios, you can have a look at this article it should clear your doubt.
https://blog.dronetrest.com/flysky-radios-and-receivers-which-one-should-you-buy/#:~:text=On%20the%20surface%2C%20both%20the,i6%20only%20supports%206%20channels.&text=The%20IrangeX%20I6X%20is%20just,that%20one%20if%20you%20wish.
I would go with the Fs-i6x save few rupees! the Fs-i6s looks mainly targeted towards multirotor application based on its design!
Regards,
Mohammed Naveed