difference between Stellaris ARM Cortex-M3 and TMS470M ARM Cortex-M3

Well, a quick glance at the TMS470 home page would tell you:

 The Hercules™ TMS470M microcontroller family enables developers to easily create safety-related applications for the transportation industry.

http://www.ti.com/tms470m 

That's the key feature: they're specifically targetted at safety-critical applications, and have specific features to support such applications.

Look at the document links down the right-hand side of the page for more information on the family...

Stellaris are just general-purpose microcontrollers.

Yashpal Patel49892 said:

let us know more range in Stellaris ARM Cortex-M3

Again, look at the Stellaris page: http://www.ti.com/stellaris