[hvkumar]

Route via Kanakapura, Malavalli, Chamarajanagar, Sathyamangalam is good.
Ghat roads up and down after Chamarajanagar.
Route via Sathy is preferred because that is the most direct and currently the best condition road.
Direct route is via Coimbatore, Pollachi and Udumalaipet.
You have to pass through Coimbatore City. Alternatives exist but this is the easiest route.
Turn off at Udamalaipet and climb the ghats through Chinar and Maraiyoor.
Expect wildlife after Udumaipet after dark.
All roads are good.
In and around Munnar, you can cover Mattupetty, Kundale Dam, Top Station,Eravikulam, Panniar.
100 km from Munnar is Thekkady.
If you wish to go to Guruvayoor, take Kochi road from Munnar (NH49) and go via Kothamnagalam, Perumbavoor to Angamali (instead of Kochi), and from there take NH47 till Trissur. Go into Trissur town (off NH47) and Guruvayoor is just 25 kms away.
To return from Guruvayoor to Bangalore, you have choice of 2 routes - first via Coimbatore (and from there same onward journey route back home), which means you must come from Guruvayoor to Kunnamkulam and take the road via Pattambi, Shoranur, Ottapalam and Palakkad. Other route is to go via Calicut and Gundulpet (Kunnamkulam, Kuttipuram, Calicut, Kalpetta, Sultan's Battery, Gundulpet, Nanjangud, Mysore).