since u have rm10k to spare, keep rm5k for the engine & another rm5k for your gearbox just incase it dies.
for manual tranny on v6, u could opt for code 232(shorter ratio, clutch plate is 8.5") or 312(longer ratio, suitable for v6tt clutch plate is 9")
make sure its complete
1.gearbox
2.gear lever complete with cable
3.3 pedals, or 2 pedals enough (brake & clutch), some shops only provide the clutch pedal only, then u gotta cut your brake rubber pedal.
4.upper & lower clutch pump
5.clutch & flywheel
above could costs u rm4.5-5.5k
there are only minor upgrades for v6,
1.custom extractor - costs rm800-1k
2.crank pulley
3.cam pulley
4.aluminium radiator