Yes, As of now
Train Extended from Kerala to TN:-
Mangalore Intercity to CBE
Shornur Palghat Passenger to CBE
Mangalore Trivandrum Parashuram to Nagercoil
Mangalore...
more... Trivandrum Eranad to Nagercoil
Bangalore CHTM Island to Kanyakumari
Mumbai CHTM Jayanti Janata to Kanyakumari
Train Extended from TN to Kerala
Chennai Raptisagar Groups to TVC
Chennai Bokaro to Alleppey
Bangalore Coimbatore Intercity to Ernakulam