My honda civic speedo meter starts jumping at cold start,it jumps 0-100-150km/h even car is not in motion.Gear shifting is not smooth that time. After 8-10 km drive it shows OK.it woks fine until engine is hot.

Actually speedo meter wasn't working at all ,I took my car to canadian tyre,they replace vss ,they told me your car speedometer will jump in beginning. You have a wiring issue,but
They were not giving me proper estimate. They change rotor,spark plugs, took 700$ away
And problem is still there.

The Ignition Control Module may be bad:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-46563-4.html#post265896

This may give you insight into the problem:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-46563-3.html#post260436