An 05 Giant TCR SHOULD have a standard sized Bottom Bracket which is 68 mm wide, English Thread. If your running a double chainring then you want a 108 mm spindle length and if you are using a tripple you want a 113 mm spindle length.
Now that's just the standard but buyer beware if this advice is wrong.
'''96 Litespeed Catalyst, '05 Litespeed Firenze, '06 Litespeed Tuscany, '12 Surly Pacer, All are 3x8,9 or 10. It is hilly around here!
Your bottom bracket is almost certainly 68 mm wide and standard English threading. The spindle length you need will be determined by the crank you choose and the crank's manufacturer will be very specific as to what is correct.