Giving either of them is ok actually. And for preparations then if you plan to shift in 2021 try to give the exam in around November 2020 if possible and to start it's preparations, as per me it's a 3 months regular studies required to crack the same. So you can start in around July/August to be well prepared to give the exam.

Either the IELTS or the TOEFL is required as part of your application to an English-speaking university and will demonstrate if you will be able to understand the course material.

The IELTS and TOEFL exams are two of the most accepted English proficiency exams around the world. However, both of these tests are different in their structure, approach, and teaching criteria. This means that you need to understand how the two differ before selecting which test to study for and ultimately take.

Thank you.