Hyperterminal should work OK. You (usually) want it set for 9600, 8 data bits, no parity, one stop bit (9600, 8, N, 1 ) and you want NO FLOW CONTROL (no software, no hardware ... none ... unclick everything).
I say "usually" because some routers bought used may have been reloaded through the serial port, and the person that reloaded it may forget to reset the terminal parameters.
If "9600,8,n,1" doesn't work, try 115K and work down from there.
We are pleased to announce availability of Beta software for 16.6.3. 16.6.3 will be the second rebuild on the 16.6 release train targeted towards Catalyst 9500/9400/9300/3850/3650 switching platforms. We are looking for early feedback from custome...