If you read Periphery 1e, there is no mention of the TC using Nukes during the RW- they did use chemical weapons and possibly Bio Weapons but no explicit mention of nukes- in at least 1 case it mentions the TC used high explosive and incindiary weapons against the SLDF invaders. The use of nukes really appeared during the Periohery uprisings in the 2760s. (I did not re-read H:RW and I don't remember if they retconned Periphery 1e in it.).
So to answer your question, while the TC probably had nukes I doubt they had tactical scale weapons- they probably had mainly space based nukes for use against warships. Keep in mind the Concordat (as originally presented ) was not interested in expansion through conquest. From their founding to the 2570 the Concordat fought to defend itself, the only time they started a war was Ariana's War against the Capellans. So if their focus is on defending their worlds, they probably did not want tactical nukes- do you really want to nuke your planet to save it from invaders?
