I have taken an admission at Shaheed Bhagat Singh College for an Economics (Hons). Further, if I get KMC or Ramjas, should I give up SBSC for any of these north campus colleges?

Choose KMC or Ramjas college over SBSC because these are better options. When it comes to academics KMC and Ramjas are definitely better than SBSC. There are reasons why the required cutoff for these colleges is more than SBSC. KMC and Ramjas also have better rankings. Many times these colleges were featured among the top 10 colleges in India. Also, if you want to pursue higher studies like M.A in Economics from DSE, then being from DSE will help. As the student crowd is more competitive at the north campus.