From a scheduling standpoint, there are a few scenarios:
First, one advantage for TAR is that it is an existing series that does not need much introduction. So if something fails, CBS can plug it into that hole without a huge promotional push needed for another brand new show to replace a failed brand new show.
-Replace a rookie failure
CBS' new fall dramas are "Bull" (Tuesdays 9pm), "Pure Genius" (Thursdays 10pm starting Oct 27), "MacGyver" (Fridays 8pm)
Since "Pure Genius" premieres so late, it'll at least last until January. "MacGyver" is a big property CBS wants to be a huge hit, but if it starts low and collapses to sub-1.0 ratings, it'll get yanked early. Even more for "Bull" on Tuesdays, but it's got a cushy NCIS sandwich to prop it up. They are not going to yank any of the veteran shows early. And only catastrophic failure of any of the new shows will bring TAR on the air before the end of 2016.
-TAR could be the bridge between the two seasons of Survivor on Wednesdays at 8pm or any other show really. Similar to how "Undercover Boss" has been used to fill in holes during the Christmas/New Year's break. This could possibly mean a shorter Race too, just like TAR12.
However, if TAR were meant to be a bridge for Survivor seasons, CBS would've said so just like how they announced "Undercover Boss" would serve as a bridge between TAR seasons before.
-Late Season Failure
TAR could also be used to fill in if one of the network's new midseason dramas fail or they end existing dramas early with no midseason hiatuses. That won't be until at least March or April.
If TAR films this Summer (2016) as usual, CBS may just keep TAR29 on the shelf and end up burning off the show in the summer of 2017. This is probably the worst case scenario. And if we've reached this point, then TARUS will officially be dead.