The train is a small world moving through a larger world - Niraj Kumar

Taxi/ Cabs are easily available outside the KGM stsn.. Standard rate for Kathgodam - Nainital in 4 seater cab is ₹400-500. in diwali season.
and ₹700 - 1000 in summer season (April, may ). Summer is the peak season for Nainital,. but if u want to explore real view of Kumaun Himalayan Range..(Nainital) than the perfect season is post Diwali period. and for snowfall its Jan end to mid Feb.. (depends on weather)..
While picking cab, U may be cautious and awaked.. As many cab driver will follow you.....
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by saying u ₹1000-1300. for Nainital.. But if u are smart in bargaining.. than they will take you in ₹400-600.. As. on my trip on 22/10/17. I got cab in ₹450.. .
As per pic1 . This is the point where ur Cab will drop you in Nainital..(Near Naini lake, Bus stand).. They won't go further this point..