Will U.S colleges still accept SAT results after April if the deadline for application already passed for the August 2018 intake ?
Do you mean the school had a November 1 deadline and you want to take an April SAT?
Check the website for the school. Many will state the last date you can sit for the SAT and have the scores arrive in time.
However, in general, schools that have November 1st deadlines are EA/ED schools who will be making decisions by December. Those schools will not wait, obviously, for an April SAT score.
Some schools have much later admission dates than most. So, not having your SAT scores until April won’t help, but it doesn’t mean you will be completely shut out of some colleges for August