Iam already pursuing MSc International Business from University of Lincoln,UK.Can I do MBA in UK after i complete my first masters degree?

Hi, Yes, you may surely pursue MBA, however please remember in order to pursue MBA from good universities in UK, you need to have atleast 2-3 years of full time work experience after graduation. Besides work experience you also need to have good academic record, plus you need to take below mention

You can do your MBA UK after completing your Masters Degree, there are no restrictions in doing second masters degree as long as you have the right pre-requisites and the needed GPA.