South Indian Adult Movies

All regional movies are different .
I think this question assumes north India as sans South india.

Better classification would be:

South Indian movies ie Malyalayam, Kannada, Telugu and Tamil
North Indian ie Punjabi, Bhojpuri(?)
East Indian ie Bengali, Odia
West India ( Gujarati, Marathi)

Bengali and Malyali are known to have strong art inclination and strong socialistic messages.
Both have hugely progressive audience markets and have produced very talented people.

Tamil, Telugu are known for their mass appeal and huge commercial markets. They are known for their exaggerated gender images, dramatic action sequences and beautiful songs. They rule the stereotypes of South Indian movies.

Punjabi movies are known for their comedy dialogues .

Bhojpuri movies are, well .. bhojpuri. Rural life is the theme in most movies.

Odia movies have very sentimental storylines.

Marathi and Kannada movies are good masala movies.

Basically all states follow Bollywood model only.

Most regional movie industries are struggling industries with a few successes .
South Indian industries have carved out a strong identity and faithful market for themselves though. Especially Telugu and Tamil, they have even followers from by other states too.