Yes, Used Car Loan Interest Rates are higher than New Car in India and difference is substantial too.
Where Interest Rates ranges from 11%-13% on New Cars - in Used Cars - it ranged from 15%-19%
Also, Banks fund Used Cars - which are presently Owner Serial 1. Apart from this - Used Car Finance Maturity Date can not be more than 8 years from date of first registration of car. For eg if a vehicle purchased by the first owner is Apr 2006 and you looking to buy this car then Bank will fund you loan for 6mo+12+3mo = 21 months (June12-Dec12, Jan13-Dec13 n Jan14-Mar 14) been vehicle completing its 8 years in Apr 2014 from its first registration date.
In terms of documentation - apart from regular documents - you need to submit a photocopy of RC and Insurance