Congratulations on recieving the offer!!!Once you recieve the offer, you will recieve an link /portal from cognizant and asks you to upload all the basic documents like your schooling, +2,graduation certificates and your last company payslips and offer from your previous company.Later on they will clearly guide you whats next.There will be an NPR ID or something like that, which can be filled with six zeroes.Hope this helps.Sanjana