bro i purchased it in 2011 september
1. no bro im not changing head unit
2.very shitty speakers bro i also dont know the brand
3.i want average bass and speakers in which sound does not cracks.
4.3000-3500 max :(
I think you've got the setup from Maruti only. They usually provide Kenwood, Nippon or Sony. For 3.5k budget, buying without bill or warranty is the best bet.
For coaxial speakers, look out for Pioneer or JBL 6" Coaxials. Buying the same set of speakers for the front and rear would be fine as your budget is limited and so are your requirements. You can do the research online and if the price is right, you can order via Snapdeal. You will get bill as well as warranty. JBL has a slightly bright sound and will give low but clear bass at high volumes, whereas Pioneer will have a muddy vocal sound at high volumes, but respectable bass. If possible, you can demo the speakers at a car audio shop and decide your preference.
We are looking at Rs. 1500-1800 speakers as you will be ordering 2 pairs and it should not exceed Rs. 3500. Do note that labour charges (about Rs. 400 or so) will be applicable if you are'nt fitting them yourselves. Check out the Pioneer G Series speakers (TSG625 I think) available on Snapdeal for around Rs. 1200 and JBL CS6 available for around Rs. 1600. I would personally say Pioneer as you have to add spacer rings also which would cost around 150-250 per piece. If you are willing to go above Rs. 3500, get the JBL CS6 as it has good reviews too and is capable as a coaxial.