In India, for the most part, there are two kinds of racks/carriers available to transport your bicycles – trunk-mounted or roof.
Features
Roof-mounted racks are the most secure for bicycles, but they are the most difficult to use. They require you to lift the bike to the roof of the car and sometimes removing the front wheel. Trunk-mounted racks are the least stable. They are easy to use but do block access to your trunk when mounted.
Cost
For each type of bicycle rack (roof, trunk) the cost will increase with the number of bicycles you wish to carry. Trunk-mounted racks are generally the least expensive.
Other facts
Consider how often you will use your rack. Trunk-mounted racks take the most time to set up. Consider how often you will host friends and family with bicycles before deciding rack capacity. Finally, consider the value of your bicycles. Trunk-mounted racks are the most prone to theft and the bikes can shift underway, causing damage to the paint. Many roof racks offer locking systems to help avoid theft.
Read more: http://www.livestrong.com/article/386130-bicycle-rack-size/#ixzz1NtikiEcs
Choices in Bangalore
1. Thule racks are available in both forms (roof and trunk). They are known to be solid, but you pay for what you get. They are available at Methods and WheelSports
2. Saris racks are also available in both forms. They are available at Pedals&Wheels
Prices (as of Apr 20, 2011).
3. KYNKYNY makes a roof-mount rack that fits most cars. Contact KYNKYNY for details. Brochure found here
Prices (as of July 31, 2010).
4. Decathlon sells a trunk-mount rack (3 cycle) for approx Rs. 7000. Source (Please add more information if available)
5. BSA Trunk Mount rack (3 cycles) for Rs. 2800 Source Available at RR Cycles.