I just bought a Robertshaw 9600 programmable thermostat to replace Robertshaw 9500.
My old thermostat ( Robertshaw 9500 ) has R, W, Y, B , O , G with R(ed) connected to RC and others connected to their corresponding colors.

New Thermostat has only RH, RC, W,Y,G. There is no room to connect B(lue) and O(range). Can anyone guide me as to how to connect these wires. Should tape Y & O and ignore them ?

Thanks a bunch for your thoughts.

You purchased a conventional, not a heat pump thermostat, so it won't work.

You need a 1H/1C heat pump thermostat. 1H means 1 stage of heat.

There are only a few stats that use O and B together and they are usually used for zoned systems. A lot of stats are using O or B. You just change the active cool or active heat in the setup.

You do need to determine which of O or B is used in the air handler.

B can be (24 Vac Common) in some Trane units.