If you are using a Tekin RS, you will need to update the firmware to vegas2.12, but yes, you can select various timing profiles in the ESC from zero timing (blinky) up to the two custom profiles where you can add boost/turbo to the point of blowing the motor if you aren't careful.
The classes at your local track will determine how you set everything up. If they offer a 17.5 zero timing class then you will set the ESC to that mode and you will want an FDR much lower than if you were running boost. Some guys gear as low as 3.8FDR for 17.5 blinky.
If they only have 17.5 super stock (open ESC), then you would gear between 5.6 and 7.0 (depending on track size, flow and several other factors) and use one of the custom profiles to add boost and turbo. I race in this class and as an example, on a 90x45 flowing layout carpet track with a Duo3 motor my FDR is currently 6.0. I use 50 boost, range 5000-17000, 11 turbo, ramp 2, delay 0.04. I previously used a Tekin Redline and was geared around 6.4
If you try to run zero timing in a class that allows boost, you will get run over.
As an FYI, that stock 87tooth spur on your TC6 is 48pitch, so you must use 48pitch pinions with that.
To calculate your Final Drive Ratio: Spur divided by Pinion multiplied by the internal ratio (for a TC6 the IR is 2.0). So its (87/pinion)x2=FDR
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