It's worth mentioning that during the 3SW the practise of ransoming a damaged 'Mech back from the victor was common. While there's probably variations between different tournaments and leagues, I'd think that the loser paying the victor would typically be in lieu of surrendering their 'Mech. (How those rights are affected if the Mechwarrior dies is another question that probably keeps lawyers happy).
Also there would be a difference between contests between owner-operators and contests between stables, which are more organised and less likely to risk their equipment. The 'big league' we see Justin and Kai competing in, located in Solaris City and with the annual champion of Solaris VII, must sit atop a hierarchy of lesser tournaments and leagues that prove additional spectacle between the big events and lets the major stables recruit talent rather than having to try out unknowns.
There would also be novelty matches like the one from the first Black Thorn novel, where the 'Mechs had all had their weapons disabled. Like most things on Solaris, the rules are the result of negotiation and change over time.
The Mechwarrior's Guide lists a surrender bond which is lost only of a Mechwarrior surrenders, not if he loses. It describes leagues, where each Mechwarrior fights each other Mechwarrior and winning is a matter of points accumulated across the season (3 for a win, 1 for a draw, 0 for a loss) and compares it to championship matches which operate elimination tournament style, either single elimination or triple elimination (best of 3).
The Grand Tournament likely picks contenders from some form of league arrangement with the top Mechwarriors in the league placed into the tournament and seeded according to their ranks (highest scoring start paired against lowest scoring, etc.). A five day schedule suggests single elimination matches starting with 32 Mechwarriors (the format would be very similar to Clan Trials of Bloodright, and might be where Nicholas Kerensky derived the notion), which is cut to 16 by the second round, 8 for the third round, 4 for the fourth (semi-finals) and then there are two contenders left for the final match on the fifth day.
If the matches all take place in the five Class Six arenas, it would probably be difficult to operate more than 2 matches a day for the arenas so the schedule is likely something along the lines of:
Day 1: first ten matches of round 1 with each arena hosting two.
Day 2: remaining six matches of round 1, first four matches from round 2
Day 3: remaining four or more matches of round 2, all four matches from round 3
Day 4: 2 semi-final matches
Day 5: 1 final matches
However this would have some flexibility: if a match is a draw the customs seems to be to re-fight it, so any draws on Day 1 would get refought on Day 2, which could push round 2 matches back (in the unlikely event that more than 4 rematchs are needed I'd expect alternate arenas to be available since otherwise it overflows). Then on Day 3 rematchs from Day 2 take place - which can push the round 3 matches back. This could get pretty gruelling since it could leave someone fighting twice in a day (actually quite likely on Day 3 or 4 depending on slot).
An alternative would be for there to be only 16 participants with 3 days of fights and 2 days 'slack' between them:
Day 1: eight first round matches
Day 2: rest-day (barring rematches)
Day 3: four quarter-final matches
Day 4: rest-day (barring rematches)
Day 5: semi-finals and finals