Fees varies in all colleges.
After completing your 12th class you can apply for various degree or diploma courses in Pathology. But, its better to pursue degree course instead of doing diploma course as it provides in-depth knowledge of the subject. Duration of the diploma courses in two-year and degree course is 3 year.
A master's degree in pathology is the minimum level of education required to become a pathologist.
You can take various specialisations which include

Hematology
Plant Pathology
Chemical Pathology
Cytopathology
Neuropathology
Dermatopathology
Forensic Pathology
Paediatric Pathology
Surgical Pathology

Good Luck.