The value of a firearm will depend on the specific model, and the condition of the firearm. Some models are more desirable than others, and will command a higher price. A "new-in-box" gun is worth more than a well used firearm.
Ruger makes both 22 rifles and 22 pistols- which command different prices. You have not provided enough information to answer your question.
ruger bearcat 22 blue and brass serial # 62155
Impossible to value on just the serial number. Call Ruger and they will tell you how old.
$100-250, depending on condition.
25-325 usd
The Ruger website shows that serial number range to be late 1974 to early 1975.
$100-250, depending on condition.
50-500 depending on specifics
50-300 usd
10-200 usd
$150-$200
10-1000 USD depending on specifics
Depending on condition, $150-300.