Has there been a game in in a tie in college football?
Yes. Prior to the institution of overtime in 1996, any game that
had a tie score at the end of four quarters officially ended in a
tie.
Numerous games across the country in each division ended in a
tie each season.
For example, the winningest program in college football history,
the University of Michigan, has an overall record of 901-314-36,
meaning the Wolverines have won 901 games, lost 314 games, and tied
36 games.
Now that overtime has been instituted, a game ordinarily cannot
end in a tie.
However, if a game were prematurely ended prior to the end of
the fourth quarter by a mutual agreement between the programs for
an extenuating circumstance (say, severe weather), and the game was
in the second half, it is technically possible to conclude a game
in a tie if the score was tied at the time the game was halted.