Kerala

Yes you can explore about part time Ph.D. regulation in India. Universities like LPU, IGNOU Anamali offer Ph.D. with various option of attendance for working people. Specially LPU gives various type of Ph.D. attendance options.
Working people can opt for part time ph d fron institutions like IIFT, IIT , IGNOU, LPU .LPU give many types of option to attend classes for Ph.d.

To get into a college in Kerala you have to write the KEAM examination that is held every year.

Yes it is possible.

The main colleges that offer criminology are:
University of Kerala, Thiruvananthapuram
Sree Sankaracharya University of Sanskrit, Kalady
Kannur University, Kannur
Mahatma Gandhi University, Kottayam.

A few colleges for forensic Science near kottayam are:
Mahatma Gandhi University (government college), St. Berchmans College, Alphonsa College, Assumption College
Baselius College, Marian College,. .

A few colleges that offer B.Sc. In Astrophysics are :
University of Calicut, Malappuram
St. Thomas College, Thrissur
Sree Narayana College, Kollam
Sree Sankara College, Kalady
Nirmalagiri College, Kuthuparamba
St. Xavier's College for Women, Aluva
government. College, Chittur
St. Mary's College, Thrissur.

Yes, you can enter through NRI quota or management quota if you have written KEAM.

A few colleges that offer MCA course in Ernakulam are:
Rajagiri School of Engineering and Technology, FISAT Business School, St. Albert's College
Cochin University of Science and Technology (CUSAT), SCMS School of Technology and Management and Mar Athanasius College of Engineering.

The most rated and well known engineering colleges in Kochi are Rajagiri College of Social Sciences, CUSAT and Maharjas college. Barath math college is a well reputed college.

The main colleges that offer criminology (which is a 2 year course )in Kerala are University of Kerala, Institute of Management and Technology (IMT) and St. Xavier's College for Women.