I want to be project manager; now my job is .net/web developer . What is the best way to become a project manager and what are the minimum years of experience needed?
My suggestion would be for you to review the current job description requirements at the companies for which you want to apply for the project manager role.
Many companies are not necessarily looking for candidates with a master's degree for this role. Some companies ask for professional organization credentials and others do not. Some companies will have different levels of project managers with different education, credential and experience requirements.
If you think that your education and experience currently qualifies you for the project manager role, large companies often have human resources professionals that assist employees with promoting to roles within the organization. Have you considered applying for the role at your current company?
If you do not think that your education and experience currently qualifies you for the project manager role, the same human resources employees at the company that could help you promote can help you identify your training deficiencies and even enroll you in training programs to help you promote.