I want to know can internet used on tablet through sim card in Videocon Vt75 tablet and can we share internet form it to PC ?
I want to purchase this tablet but if there is on internet support then I will not buy it.

Yes, you can use internet on this tablet using SIM but you can only use GPRS and EDGE because there is NO 3G available on this device. And android can share internet through mobile device to PC easily, you can use USB tethering to do so.