Hi Sangeetha,
Nokia 6303 is better than 5130 in terms of features. Please find some of them listed below.
Nokia 6303
Display: 16M colors
Camera: 3.15 MP, 2048x1536 pixels, autofocus, LED flash
Battery:
Standard battery - Li-Ion 1050 mAh (BL-5CT)
Stand-by: Up to 450 h
Talk time: Up to 7 h
Frequency band: 2G: GSM 900 / 1800 / 1900
Nokia 5130
Display: 256k colors
Camera: 2 MP, 1600x1200 pixels
Battery:
Standard battery - Li-Ion 1020 mAh (BL-5C)
Stand-by: Up to 288 h
Talk time: Up to 6 h
Music play: Up to 21 h
Frequency band: 2G: GSM 850 / 900 / 1800 / 1900
Overall Nokia 6303 fares better in terms of features and looks (personal opinion). I would suggest, once you go to the shop, hold the phone in your hand assess your feel this is the phone you want, then go for it.
Best of luck for your phone purchase
-Lakshmi