hello,

there are many subfields that you can specialize in . these are some popular branches of psychology:

• Diploma in criminal psychology
• Diploma in Applied Psychology
• Diploma in Behavioral Sciences
• Diploma in Cognitive Neuroscience
• Diploma in Behaviour Analysis
• Diploma in Clinical Psychology
• Diploma in Family Psychology
• Diploma in Child Psychology
• Diploma in Cognitive sciences
• Diploma in Counselling
• Diploma in Cognitive Behavioral Therapy
• Diploma in Behavior Support

hope it helps,

all the best.

Dear Aspirant ,
Yes,you can do diploma in many major branches of psychology both in India and abroad .
You can consider the following branches -
1. Clinical psychology
2. Counselling psychology
3. Applied psychology
4. Social Psychology
5. Child psychology
As far as Animal psychology and I/O psychology is concerned they are not really offered here in India and it is best if you pursue it from abroad.

Hope this helps!