Interviewing has come a long way. The entire process of an interview has changed drastically and it is not what it used to be a decade ago. With globalisation changing the face of India, the interviewing technique has become more of a friendly conversation in order to identify the competencies of a candidate rather than a grilling session.
When there are so many changes in the way interviews are conducted, it is normal for the interviewee also changing a bit in order to adapt to the interview. This is true. The way you would appear for an interview has also changed.
Your dress gives the first impression to the interviewer. This still holds good. But it does not mean that you have to be dressed in a formal suit with a tie. A normal and simple attire even if it is a jeans and T-shirt will do, till the time it is clean and ironed and does not give a shabby and disorganized look. Whatever you wear you should ensure that you give a clean, organized and civilized look.
Your shoes is another aspect that is to be taken care off. Here again you need not be wearing a pair of formal shoes, polished and shining. A good pair of shoes will do, but you need to ensure that it gels well with your dress.
A simple appearance is the key. The interviewer tries to assess your basic competency of discipline, from your appearance. He is looking to hire a person who knows what he is doing, who is organized, who is serious about what he is doing and who he knows is going to be around for some time.