You can register for the IELTS test online through the official IELTS website (https://ielts.org/take-a-test/preparation-resources) or by contacting your local test center. The registration process typically involves choosing your test format (paper-based or computer-delivered), location, date, and completing an application form. You'll also need to pay a registration fee.

There's no limit on the number of times you can take the IELTS exam. You can retake it as many times as you need to achieve your target score.

IELTS scores are generally valid for two years from the test date. This means most universities and institutions will accept your scores for two years after you take the exam. However, it's important to check with specific institutions as some may have shorter validity periods.

The wait time for your IELTS score depends on the format you took:

• Computer-delivered: Results are available online in 3-5 days.
• Paper-based: Results are available online in 13 days.

In this case you have to use an IELTS Test Report Form (TRF).‍

• During registration: When you register for the IELTS test, you can indicate which institutions (up to 5) you want your scores sent to electronically for free.
• After results: You can request additional TRFs (electronic or physical) to be sent to other colleges for a fee.

Universities will consider your highest score from all the IELTS attempts you've taken. You don't need to inform them about previous attempts, as they only see the score report you submit with your application.

It is not mandatory but it's suggested to have the IELTS score with you while applying to universities.
Here's the breakdown:

• Some universities require it: These will clearly state the IELTS score as part of the application requirements.
• Many allow for conditional offers: You can apply without the score, but receive an offer on the condition of achieving a specific IELTS band by a certain deadline.

It’s recommended to always check each university's website for specific requirements.