hi neha,
first of all i need to know whether your project pertains to a particular department or the whole orgn.
neways what you can do is
1) design a questionnaire depending on the department/s you are goin to interview.
eg) if interviewing the hr u can use hr jargons and terms in your question whereas any other dept will require to be asked in a laymans language.
2) once ur questionnaire is drafted, select a sample of employees to int. take a mix of emloyees across the hierarchy.
3) int them, get their feedback. analyse each interviewee and try to fig out if he fsll in the satisfied or dissatisfied category.
4) if your sample is large use a software like spss or any other software or else work manually on the statistics.
5) also look up into exit int forms and try to find out reasons for people leaving the orgn.
5) finally make a presentation with the various statistics, suggestions from employees and your own recommendations.
all d best.