Hello Raghul,
Sri Krishna college of engineering and st.joseph college of engineering are one of the top colleges in TAMILNADU.
As per rating wise SRI KRISHNA COLLEGE OF ENGG,TAMILNADU has higher rating than ST.joseph college of engineering.
Sri Krishna clg of engg is also autonomous.
Both are good colleges.
Rating of SRI KRISHNA CLG  is 3.9.
Rating of St.Joseph CLG is 3.4.

Hope this may help you.
All the best!!

Hello aspirant, 

Both St. Joseph College of Engineering and Sri krishna  Engineering college are one of the top colleges in Tamil Nadu.So it depends on the bracnch you are interested in.

For more information please go to the link:

https://engineering.careers360.com/colleges/ranking/2018/top-engineering-colleges-in-tamil-nadu