Hello Adnan,

Congratulations on graduating the 12th grade. Now is the time to decide the route of your career which may very well shape your life ahead from this point on. Before selecting any of the available options, you have to be aware of your interests, the things that you are good at and the field of studies that excite you and make you want to explore it further.
As you mention that you are interested in pursuing engineering, you need to understand the basic requirements to be a good engineering.
1. You need to have a good understanding about the science concepts and be fairly good at it.
2. Mathematics is a fundamental concept that lays the base for everything.
Coming to the suggestion given by your family members, it is important to realize the implications of your choices here on out. The path chosen from this point will determine the route of your career. I would suggest that you think extensively on this topic, and listen to suggestions given by your family members, consult people who have chosen both the career paths in questions and weigh your options before finalizing on a decision.
Good luck.