They are 3 types of tickets
1. RS 300 Shegra Dharshan tickets issued 3 months in advance for which you need to register I'm TTD website or app and tickets will be issued on every 23rd date. After Darshan ticket issued you can book room on that date
2. Free Darshan or Sarva Darshanam which is general que which will...
more... take 12-24 hrs depending on the day and rush, avoid weekends and festival holidays.( have to stand in que continously and cannot get back )
3. Footpath steps Darshan tickets will be issued for first 10,000 pilgrims for climbing up the hill. Collect token between at foothill in morning 3-6 AM and climb the steps at 2000 steps you will be issued ticket with time slot which will take 6-12 hrs.
4. In Srinivasam complex opp Tirupati RTC Bus Stand everyday morning 3-6AM and Alpiri Bus stand you will be issued free Darshan times slot tickets with time slot mentioned you can directly go at that time into Que.
For 1, 3, 4 after entering into Que at the time slot will take 3-6hrs depending on rush and number pf pilgrims waiting in que. The principle point is you need to have patience and desire to have Darshan without closing your eyes.