Business Attire is required, that's how I dressed up during my interview. The interviewers were very welcoming and asked in-depth questions to examine my suitability for various positions. Yet, dressing up essentially varies according to the position you are applying for.
They don't really care. When I went for an interview, the interviewer didn't even look at me.. She was so rude and had no basic etiquettes. She didn't even say hi to me. She was only interested in making money. This is a worst place. There don't have real jobs.
They don't care what you wear. They only care about making money out of you.