I am using IBM Cplex for C# in the visual studio and the outputs are different from IBM Cplex Optimization Studio outputs. The code is same, constraints and datas are same and I am expecting also output is the same but it is not. What is the reason could be? Is there any setting or something?

As the first step, try to compare model statistics in engine logs. If the engine logs are different, the two models might be different. Even if they have the same statistics, if the ordering of constraints or variables are different, you might still see different solutions.

However, as long as the two CPLEX models are indeed mathematically equivalent, you should expect the same or nearly equal objective values.

If you need further discussion, please open a case if you are entitled. Otherwise, please discuss your question in Data Science Community https://community.ibm.com/community/user/datascience/communities/community-home/digestviewer?communitykey=ab7de0fd-6f43-47a9-8261-33578a231bb7&tab=digestviewer