After the Open Doors offer or invitation stage, students move from admission processing into travel and enrollment processing. You may need an official invitation for visa purposes, a Russian student visa depending on citizenship, medical insurance or health documents, dormitory confirmation, arrival instructions and final university enrollment.
Do not treat the winner result as permission to travel. The safer sequence is: winner result, post-selection documents, university processing, offer or admission confirmation, invitation/visa instructions, visa approval, travel booking, arrival, migration registration and final enrollment.
The exact process changes by country and university. A Pakistani student, Indian student, Nigerian student, Bangladeshi student or European applicant may face different embassy requirements and timelines. Always follow the receiving university and relevant Russian embassy or consulate.