Hi Gialli
The TLC272 model on the product website is available in an unencrypted format, so you should be able to import it into older PSpice versions such as 10.3, Please download the specific .lib file you need to use, there are 4V, 2-5V and 2-10V parts. There is a readme file in the .zip it as well.
However, if 10.3 is a student version with node limits, you might not be able to simulate it and need to go to a higher version.
Regards
Ranjani