I speak British accent, but I'm studying TOEFL . And as the TOEFL is the test of America, I choose a American teacher. But I also want to maintain my British accent, so I may also need to find a British tutor. Shouldl I change my pronunciation?
To maintain a British accent you would need to be speaking with Brits more than Americans.
An American or British accent should not make a difference on your ability to pass the TOEFL.
It doesn't matter if you use British or American pronunciation.The important thing is to be consistent,and not change from one to the other.Choose whichever one you are more comfortable and familiar with and stay with it.Don't switch back and forth all the time (unless you are an actor!) You should also be consistent regarding vocabulary, using words from UK or US English as much as possible.