I frequently travel to Trichy. Here are route suggestions to reach Trichy. By all means, avoid the stretch between thotiyam to kulithalai which is horrible!!
Here is the route suggestion.
All of us know that bangalore to namakkal is a breeze. From namakkal, take the one to Thuriyur via Tattayangarpettai and From Thuriyur to Trichy is via pulivalam and mannachannallur. This is a much better route. Hope this helps one!