K10B engine dose not have timing belt it's having timing chain you can see part of it through the engine oil filling port (after opening engine oil filling cap) it is good for at least 100K miles / 10 years even 15 years if all periodic maintenance is done on time.
Life Span of clutch is totally dependent upon Driving habits . Bad driving habits such as clutch riding ,using vehicle for learning driving etc .will reduce it to 20-25% expected service life.
nice article to find if your clutch have problem,i have linked below.
however there is one condition which is a matter of owners preference ,that is clutch pedal becomes harder during its life span due to hardening of pressure spring in clutch assembly it not mandatory to get clutch serviced only on the basis that clutch pedals feels hard.