These are a few very good colleges in Tamil Nadu if fees is not a constraint for you. And all these colleges accept CAT scores and few of them accept XAT and CMAT scores also

• IIM Trichy 
• Great Lakes Institute of management 
• LIBA Chennai 
• IFMR Chennai 

Apart from these colleges there are many colleges that accept TANCET scores 

• Anna University 
• Thiagarajar school of Management 
• PSG college of Technology 
• University of Madras 
• Kumaraguru College of Technology and other private colleges 

Good luck