Hello,
.
Here are the best post graduate diploma courses in India that gives you a bright Career,

PGD in management,

• Business management
• Human resources
• Businesses marketing
• Financial management
• Business administration

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PGD in arts,

• Public relation
• Public administration
• Teaching of English

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And you have many other fields in diploma accordingly to your intestinal like,

• PGD in medical
• PGD in law
• PGD in engineering
• PGD in paramedical
• PGD in education and so on

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Now, first think about your interest and then go for course selection. That will be Easy to choose a career.
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Best of luck