I have a track power esc. Can anyone explain what boost start and boost end rpm means ?

It's the RPM range that boost(timing) is applied. If you are running Blinky, you can't use this.

From the manual:
http://manuals.hobbico.com/tkp/tkpm0050-manual.pdf

Boost Start RPM: Sets the start RPM range.
Boost End RPM: Sets the end RPM range.

Boost Timing: Adjusts the amount of timing within the set RPM range selected in Boost Start RPM and Boost Start RPM. Example: Boost Start RPM = 10,000 RPM, Boost Stop RPM = 20,000 RPM, Boost Timing = 20°.
This means that there is 20° of Boost Timing in the range of 10,000 RPM and 20,000 RPM.