Trending @Wipro; Need your inputs

I worked on a support role for 3 years and on a developer role for 8 months. I have a great confidence in the support role I worked. But the developer role as I have only 8 months experience, Iam not pretty confident and I have no deep knowledge in that. Now I am trying to switch company. My sister who is also a techie and a developer, asked me to study the developer role throughly and try outside stating I have 4 years experience in that. I am bit confused is that a good idea? Studying without enough experience can crack an interview? Is support roles are bad and have no future? Please give me suggestions.