In the Kailash Yatra, after the immigration process, the customs clearance process takes place at the Nepal-Tibet borders. The Kailash Yatra group members must move in a proper queue and follow the instructions of the Tibetan guide. In the custom clearance process, just the bags and luggage are scanned thoroughly in the scanner. The customs clearance process for the complete group takes about 20 to 30 minutes.

The Kailash Mansarovar Yatra takes place through 2 routes- one is by the Heli route and the other is by the Overland route. The immigration process takes place at the Chinese Immigration Center on the Nepal-Tibet border. Hilsa is the Nepal-Tibet border on the Heli route of Kailash Mansarovar Yatra and Keyong is the Nepal-Tibet border on the Overland route of Kailash Mansarovar Yatra. The whole Kailash Yatra group enters and exits from Tibet together.
First, the immigration takes place at the Nepal immigration camp where the details of the pilgrims are noted down and the Nepal exit stamp is put on the passport. When the whole group reaches the border, the Tibet entry process takes place at the Tibetan Immigration Centre. The Passport of each member, Group VISA, and Group Permit are checked and entry is done through the Immigration system. Biometrics, i.e. fingerprints of all 10 fingers are taken but no stamping on the passport is done. There is some waiting time seen at the Immigration Centre. 
The time taken in the Immigration process depends on the size of the group. However it is a tedious and time taking process, so do not hurry up be patient and cooperate with the authority at the immigration centre. It is advisable to maintain discipline at the Chinese Immigration centre and follow their instructions.