Send a single pulse low/high pulse then stay high
Yes, You don't need connect this pin to MCU. there are some possibilities to save one pin on MCU:


connect directly RES# pin to VDD (although this is not recommended, I see this in some applications and it is working)
try find existing reset signal with right polarity on your board (external reset of AT tiny)
add RC with diode which make short pulse after power-up, like:


100nF between RES# and GND
10kOhm between RES# and VDD
one diode from RES# to VDD