Competent Groove Node Js Developer interview questions

The package shown in the job description was 4.5-6 lpa but at the time of interview they said it will be less than 3lpa in hand as i am a fresher, then why did they post job description with experience 0-3 years. The interviewer was very unprofessional, i felt as if it was his first interview. I applied for the post of node.js developer but he asked me questions from testing, c++, oops, jdbc(almost every possible domain except node.js