first of all I got email from unam.nanotechnology center from the assistant professor that I want to take your interview on wednesday.If you have skype connection than tell me the i.d.otherwise it will be on the phone.I told him the time on which he should call.then he called me on wednesday.you will also receive the email.The number will be of no use to you because the interview will be held by the department to which you have applied.I applied to material science and nanotechnology department so my interview was held by professor of that department.he said that you will be informed about the result within 1-2 weeks.you should contact the department to which you have applied.