Test results for the Canon EOS Rebel T6 and the Canon EOS M3 are now available in the site's ISO noise comparison tool.
Hare are some comparisons that may be of interest:
Canon EOS Rebel T6 compared to Rebel T5
Canon EOS Rebel T6 compared to Rebel T6i
Canon EOS Rebel T6 compared to 80D
Canon EOS M3 compared to Rebel T6i
B&H (still on holiday break) has the Canon EOS Rebel T6 and the Canon EOS M3 in stock.