Can I study in a university in the UK if I only have the SAT, IELTS and bio ACT as an international student?

You're not comparing equivalent measures: IELTS is a specific English language proficiency test, not a general indicator of your academic achievement.

If English is not your first language, you must show that you can speak, read, and write English proficiently to succeed in a degree program taught in English at a UK university. This requirement applies to all students, including those from the UK who must pass GCSE English and Maths (or the Scottish equivalent). For international students, IELTS serves as the equivalent qualification. SATs or other subject-specific qualifications from your home country are separate and not directly comparable to IELTS.