Dual

Dual specialisation is better in terms of future concern because if you choose dual specialisation then you will be eligible to sit in the placement process of companies with both the specialisation. Example, if you have chosen dual specialisation as marketing and finance, then the companies which are coming for marketing profile and finance profile, you will be eligible for both. Dual specialisation is better since you can apply for more varieties of jobs, provided you can manage both areas of specialisation. Take your second specialisation as a support for example, if you take IT as your second specialisation, you can excel at advanced excel, database management, and further IT operations which are sought in a suitable candidate in any field.
I hope this helps you.