Both the colleges ISBF Delhi and NMIMS Mumbai offer a decent Economic Honors program. I have drawn a detailed comparison between the two on the basis of the following parameters 

Worth of the Degree: NMIMS might be a reputed college but its degree cannot be compared to that of ISBF which offers a University of London degree in addition to academic assistance from London School of Economics and Political Science, the top-ranked institute in Economics.

Curriculum: Economics is vast and covers a very broad spectrum of subjects from development and finance to international trade. Now the University of London excellently allows the students to choose 6 electives of their choice in addition to 6 compulsory subjects. This ensures that the students get a job in the sector they are passionate about. This flexibility of curriculum lacks on the part of NMIMS.

Prospects: A DU student applying to top institutions in the UK for a master, is required to complete a diploma year before starting with his master's. This aims to compensate for the difference in the standard of education. However, anyone with a University of London degree can directly apply for a Master in top universities in the UK.

Batch size: The batch size at ISBF is relatively smaller than that of NMIMS. This aids in better student-teacher interaction and class discussions. This in turn helps in better delivery of the curriculum.

So in almost all aspects, ISBF is a better choice than NMIMS.