Khalsa College used to be associated with GNDU but now it is a different university. Both colleges are good and will provide you with a great experience. Some consider Khalsa to be better than GNDU, though it is a bit expensive.

GNDU has average placements. Being on the main campus won't be beneficial, as students from the regional campus also will take part with you in the placements. Hence, increasing the demand. 

Very few companies take part in the placement program and are known to offer fewer job roles. Thus, most of the time students from the main campus receive zero placements.