Hello Karthik, your question is not very clear however i would assume that you are looking forward to start a diploma course in mental retardation in bangalore. there is no specific diploma in mental retardation however there are courses on Diploma in Mental Health or Diploma in Special Education (mental retardation)

For these the colleges in bangalore are:

• National Institute of mental health and neuroscience (NIMHANS)
• Sampurna Montford college

Other than bangalore there are certain other institutes in karnataka:

• Divya shanti special school, kolar
• TMA Pai college of special education, udupi
• St Agnes Special School, mangalore.

Admission procedures and relavant details you can find by visiting the official website of the mentioned colleges