What is the value of a red seal five dollar bill series 1953b?
In worn condition, face value only. If nearly new, $8.
There are many varieties of US $20 bills that have brown seals, but only two types were printed in the 20th century - the 1929 series of National Currency Notes and the 1934 series of wartime currency printed for use in Hawaii. Please see the questions What is the value of a 1934 US 20 dollar bill with HAWAII on it? What is the value of a 1929 US 20 dollar bill?
No US $20 bill carries a "G" series letter. You may be looking at the Federal Reserve District letter. The series letter, if any, on US bills is next to the date. Regardless, a date is needed in order to estimate a value. Please determine the bill's date and see the question "What is the value of a [date] US 20 dollar bill?" for more information.