Can the IELTS test for British immigrant visa be used to apply for other countries?

Specific situation, specific analysis.

It depends on what country you are applying for.

Different countries have different requirements.

And it depends on what kind of IELTS you take, whether it's academic or life skills.

Generally speaking, as long as you take the UKVI IELTS test, you can use it to apply for schools in other countries.