I know that the typical surgery to repair a torn ACL normally requires anywhere between 4 to 12 month of recovery time (although it obviously depends case to case as we've seen with Derrick Rose.) Rondo had his surgery on February 12, which means he could hypothetically be ready for basketball before the season starts. If Rondo takes the Rose route to his basketball return and it takes him a full year to come back, that would put him on pace to be back with about 30 games remaining on the 2013-14 schedule.
For reference, here are some other NBA players who suffered ACL injuries and their respective recovery times:
Recovery Timetables
7 MonthsBonzi Wells* (April 6, 2001)
Kendrick Perkins (June 15, 2010)
8 MonthsJamal Crawford (July 2001)
Leon Powe (April 19, 2009)
9 MonthsAl Jefferson* (February 8, 2009)
David West (March 26, 2011)
Iman Shumpert (April 28, 2012)
Ricky Rubio (March 9, 2012)
10 MonthsAl Harrington* (January 23, 2002)
Josh Howard (February 22, 2010)
Michael Redd* 1st injury (January 25, 2009) ACL, MCL
11 MonthsCorey Brewer* (November 26, 2011)
Tony Allen* (November 2, 2007)
Eric Maynor* (January 7, 2012)
12+ MonthsJason Smith* - 14 months (August 6, 2008)
Nene* - 12 months (November 2, 2005)
Adam Morrison* - 12 months (October 20, 2007)
Michael Redd 2nd injury - 14 months (January 10, 2010) ACL, MCL
Shaun Livingston - 20 months (February 26, 2007) torn ACL, MCL, PCL, lateral meniscus, disclocation of patella and tibia-femoral joint
Baron Davis** - TBD (May 6, 2012) ACL, MCL, patellar tendon
Derrick Rose - TBD (April 28, 2012)
Source:
http://jlongrc.hubpages.com/hub/ACL-Recovery-Times-in-the-NBA