On a receipt of a letter (formal invitation) from the University stating that you have been invited for study, you should apply for the entrance visa through the Russian Embassy or Consulate in the country in which you are currently residing.
The following documents are needed to come to Russia:

• a valid external passport;
• a valid visa containing information that you are coming for study (educational visa);
• a medical certificate including AIDS (HIV) test.

On arrival you should register your passport in the OVIR office (Visas and Registration Dept.) within three days (excepting holidays and days off).
You may extend duration of your visa while in Kazan in the following cases:

• it corresponds with the dates of your national passport validity;
• the reason is your interactions with KNRTU-KAI.

KNRTU-KAI cannot be responsible for the problems you will face on arrival in Russia if you have neglected these instructions.