Sir, No direct Express trains are operated from Pune ( MINI METRO ) to Tamilnadu CITIES/Municipal/Town.Advance reservation Booking to Pune is very difficult since Pune comes under Remote/Pooled QUOTA.
So operate direct train from Pune to Chennai/Coimbatore/Nagercoil.
Otherwise Sectional coaches may be operated between Pune and Tamilnadu Trains which are running from Mumbai with less than 24 Coaches.
...
more... 12163/64 Dadar-Chennai Egmore Daily expresses may be augmented from Pune to Chennai Egmore 7 Sectional Coaches of sleeper /2 AC/ 3 AC COACHES.
Similarly 11017/18 Mumbai LTT-Karaikkal Weekly Expresses by 8 sectional coaches between Karaikkal and Pune.
16339/40 Mumbai CST-Nagercoil 4 days per week and 1616351/52 Mumbai CST -NAGERCOIL via Tirupathi Bi-Weekly may be added 3 Sleeper/3AC sectional coaches between Pune and Nagercoil.
11043/44 Mumbai-LTT-Madurai Weekly Expresses may be operated 7 sectional Sleeper/3AC/2AC Coaches between Pune and Madurai.
11013/14 Mumbai Kurla -Coimbatore expresses by 1 Sleeper coaches between Pune and Coimbatore or 1 additional sleeper coaches earmarked between Pune and Coimbatore.