Samsung Galaxy Y S5360 runs on Android v2.3 (Gingerbread), an operating system (OS) that is capable of tethering or sharing the phone's Internet connection with other devices over a wireless LAN (Wi-Fi). So if you are subscribed to an unlimited internet connection and wants to make it "sulit", then share it using your Galaxy Y, and enjoy 3G download speed up to 7.2 Mbps via HSDPA (well, still depends on telco carrier and your location).
Here are the steps on how to setup your Samsung Galaxy Y as a portable mobile wifi router:
1. Go to Settings >> Wireless and Networks
2. Select Tethering and portable hotspot