Frankly Speaking Bilaspur - Tirunelveli was initially Started From Trivandrum later they extended to Tirunelveli, Even the TEN Antyodaya route is good but the main problem is timings, if it is changed it would be successful. Better a train connectivity to TEN from SBC via KPD, SA, KRR, DG MDU or SA, ED, CBE, PGT , DG, MDU and a Daily connection from CBE would be good.