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What does "it" in "make it" below refer to?

Context:

What Are the Odds? A Trainer With 5 Shots to Win the Derby
By JOE DRAPE
If all five of Nick Zito's colts make it to the starting gate, it will be only the second time in the history of the Kentucky Derby that a trainer has put so many runners in the field.
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"Make it TO university" means you manage to get to the university.
"Make it at/in university" means you're going to pass all your university exams with success. I'd prefer at/in followed by "the", but wait for other opinions.
Comments  
"Make it" is an idiom and should not be split into two separate words. "Make it" in your sentence means "manage to reach sucessfully" e.g.

"If all five of Nick Zito's colts MANAGE TO REACH SUCCESSFULLY to the starting gate, it will be only the second time in the history of the Kentucky Derby that a trainer has put so many runners in the field. "

Another example:

"If I MAKE IT to university, my father would be very happy."
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Why not used "in" instead of "to" in "I MAKE IT to university"? Could I change "to" with "in" there?
 pieanne's reply was promoted to an answer.
Thanks.

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To Jobb,

"Make it to university" means "manage to get to university" or "get accepted by a university". Whether a person makes it IN the unversity after he gets in there is a different story!