You have MSW HR degree and 3.5 years of experience in HR section. Why are you looking for an added course. Have to tried to apply for any overseas jobs? Have you worked with any Indian NGOs like HelpAge India, CRY etc?
There are many courses that you can do but it would be better to focus on a further niche area so that it would be useful for your overseas career plans.
Select a country and choose a sub-specaility field in MSW like de-addiction program management, mental health sector, rehabilition programs, support programs for abused children or adults. There are many international charity organisation with a global presence. Choose one of them like, OXfam,Amnesty international, Care international, Doctors without border etc.
Once you slect the country, then check what you have and what additional criteria that you need to meet.
For instance, this link gives you information about social work jobs in Canada (http://www.prepareforcanada.com/working/success-strategies/career-pathways/social-work/socialwork-employment/requirements-to-work-as-a-social-worker-in-canada/#.WqedrWpubbg).
If you choose MSW HR jobs in Australia, this link gives you an idea of what is needed (http://www.visabureau.com/australia/social-work-jobs.aspx).
If you choose to work in UK then choose a course that would enable you to get into the management and logistics or community/social work
2.You can choose one of the international diplomas in Humanitarian Assistance.
Tata institute of social studies offers short term programs
IFRC-TISS Certificate Program in Disater Management
Poverty and Migration related courses.
I would suggest, draw up a good CV of yours focusing on the core skills and experience, the niche areas of social work that you have handled and start applying for posts overseas. Then you will get an idea of the relevance of a short addition course and if yes, what would be it. You can even choose to study overseas and have an intership or observership that would hopefully lead on to your dream job.