The 3A caste is further divided into 3A(general), 3AK(Karnataka) and 3AR(Rural). As you have not elaborated your reservation category hence i am considering it as 3A(G).

Considering previous year cutoffs you could get these colleges:

M V J College of Engineering Bangalore

S J C Institute of Technology Chickballapur

Sri Siddartha Institute of Technology Tumkur

Tontadarya College of Engineering Gadag

Basaveshwara Engineering College Bagalkot

All the best!!