Hi there.. I'm posting this answer as per my knowledgeUsually they'll give the offer letter within a week or couple.Sometimes they might have critical requirements in the next higher level than for what you were been interviewed. So they'll promote you and offer the package higher than what you had discussed in HR round(provided your skill set is close to their expectations and they were satisfied with your performance in the interview).In such cases it might take some extra time for closing those positions. So please wait for couple of weeks or you can keep attending the next set of interviews in the meanwhile.If at all you haven't got any mail/call you can contact the HR if you have his/her mail or contact number.