the venerable T/C Renegade is a great rifle (IMHO) ... cheap, very unHC/PC, and, if properly maintained, pretty reliable. if you have a newer design lock (or one of the replacement locks) the reliability goes up even more. I think the design of the way the barrel attaches to the stock is a not what many of us are used to, and there is always the temptation towards over tightening: loose is bad, tight is good, very tight is very good...
the barrel has a hook on the end of the breech which slides into a small square hole in the tang. the tang is screwed into the wood with big honking wood screws, and not attached to the trigger guard with bolts as we normally see. I don't know if the real Hawken rifles had bolts through the tang and into the trigger guard or not. I would suspect that the T/C folks designed it this way for ease of manufacture and cost savings. (It was a relatively inexpensive gun, and it was the first ML rifle many of us owned - I still have mine after nearly three and a half decades.)
from your description, the crack involves the female part of the hooked breech system.
for what it's worth, here's what I think you should consider doing to fix the problem:
(a)bed the back (female) part of the tang... of course, you want to do this with the barrel in the tang, so everything lines up when you're done, and use plenty of release agent ... barrel, breech, trigger and guard, anywhere the goopy stuff might get into, the family cat, etc ...
(b) if the bedding compound doesn't end up in the crack, try to work something in there to stabilize the problem. I would go with TiteBond III over superglue ... the CA glues are not as good at impact resistance in my experience. I have used bicycle innertubes to get the wood back together with good result.
(c) refinish the stock as necessary. (depending on the depth of the crack, you might get away with not having to do this, or, if you're so inclined, you can use this as a good reason to refinish the rifle, and while you're at it, add some woodworking of your own ... there are some good posts around here on that very topic.
Good luck with your project, and make good smoke!