He was admitted to the university. You can use the past perfect tense here, because it is rumored that he was admitted; Of course, the past tense can also be used to indicate that the rumor itself is the news of admission)

It is said that he was admitted to the university.

The sooner you do it, the better.

The sooner you do it, the better the result will be.

The preposition used for admission is to.