Taken from their website the Away block is 115 at Liberec but I guess the info below is based on league/play offs when there's a higher demand for tickets.
GUEST SECTOR
Ticket reservation rules for FUN CLUBS and organized groups of fans of visiting teams
BASIC INFORMATION
Visiting fan clubs and organized groups of fans have an obligation to inform the home team in advance about their arrival according to the APK agreement, so that all necessary measures related to the sale of tickets and ensuring the safety of all spectators of the game can be taken.
GUEST SECTOR IN HOME CREDIT ARENA
Composed of the bottom half of the sector 115, with the capacity of 150 seats
Entrance to the sector solely by relevant entrance
Sector is close to the players’ bench of the visiting team
BULK BOOKING TIME LIMIT
At least 48 hours before the start of the game; during play-offs at least 24 hours before the start of the game
ORDERS
Toll-free call 800 800 007 (Monday, Wednesday to Friday 9:00-12:00 and 13:00-18:00, Tuesday 13:00-18:00), or landline 489 201 110, or by e-mail
vstupenky@homecreditarena.cz.
PAYMENT AND TICKET DISTRIBUTION
Cash only
Sale takes place only at the main ticket office (ROTUNDA) in the area of Home Credit Arena
CONTACTS
HOME CREDIT ARENA cash desk (vstupenky@homecreditarena.cz, 800 800 007) – ticket reservations
NOTE
If no reservation as described above are made and all the other places in the arena are sold out, all vacancies in Sector 115 will be gradually put on sale to the general public.