want to switch from Geophysicist to Geologist

are you in the us? are you in a state that licenses geologists and geophysicists?

being persistent is part of the hiring script.

Go for archaeology - Geology is for idiots.
Rocks and variations thereof... wow!
Worse than being a taxi-driver, imo.
Easy to learn, though - A 45 minute course will get you a pointless Degree in it.

i am in india.

may be you are right i should try in archaeology as well, thank for your concern.

here in india you need to have minimum 3 years of experience in the field to become a certified Geologist, and most of the companies hiring freshers from campus while others who have not been selected in campus placements or do not have work experience are struggling for a job.

will you attain relevent experience as a field geophysicist or are you just deploying geophones or resistivity probes?
Someone is your boss no?

Must that boss sign off your experience and must you sit for a test for your license?

I dont see any way to shorten that. Here in US we give a year for a year for each year of grd school (up to 3 years), the other 8 years must be in service
under a licensed geo. Also, you must collect 14 ed credits every 2 years to keep your license current.

Good for you!
You may just discover something awesome and have it suppressed by your sponsors - Rather than looking at stone-physics.