Two stage first one is technical and second one is hr if you pass technical round then hr interview comes. HR department tells you their policies and discuss salary. If everyone is ol you will get off letter within a couple of days.

Interview happens with group leader or Team Leader, for 15-20 mins. Few questions on past experience followed by general questions on chemistry. Mostly to test the knowledge. Followed by salary negotiations with HR. Mostly they have a fixed figure in mind and won't negotiate much.