Kiran wrote:(Ideally, would like to do this without modifying the JoomlaComments or jReviews code)
I think, unfortunately, it's impossible (or beyond my skill at least). We could implement code in JoomlaComment to check for JReviews and then put the entire component inside another DIV layer (which would go in the second tab) but that would depend on JReviews being already completely rendered before JoomlaComment even started - that'd be too hard to do because JoomlaComment is executed onPrepareContent.
It'd require a brand-new plugin that combines both the extensions into one... I can't imagine how much trickery and hacks it'd take.
I understand your concern though about the layout, it's not very efficient the way you have it and as far as I know there is no way to do it. However, since i'm interested in this too (I plan to use a Review component of some sort myself alongside JoomlaComment) I will investigate this mission further
...who knows, maybe JoomlaComment itself will have review capability in a future version