Never ever accept offer from this company without offer letter. They will ready to release offer only if you can join within month and offer letter will be provided only after joining formalities done. They call you to their office and show you the salary structure and get offer letter signed from you. As joining date comes close they will mail you about your offer is on hold. Over call HR tells we will contact you once we get confirmation from client and also asks are you ready to join with less compensation than already offered. And then after HR will never picks your call.