Sir
You remind me of my college days.
Get a 2 channel AMP wire it @ 2ohms to all 4 speakers.
Kenwood 5204 3,000 Rs
Kenwood Electronics Europe | Amplifiers > KAC-5204
Will give you pretty decent bass.
In future add a SUB and AMP will cost you atleast 8-12K Rs for a nice one.
Or
Spend another 4,500 Rs and get any of these SUBS in a sealed enclosure, you can also get a used Pioneer 307/308 series SUB for 2-3K Rs.
Instead of wiring the 2 Channel AMP to speakers, bridge the AMP and run SUB.
http://www.kenwood.eu/products/car/speakers/component/KFC-W3010/details/
http://support.jvc.com/consumer/product.jsp?modelId=MODL027568&pathId=66&page=1&archive=true
http://www.pioneer.com.sg/storefront2/ProductDetail/default.asp?ProductId=689&CatId=2,27,85
Regards