Thanks hellstar apart from this one I tracked the second route just before Sriperumbudur:
a) After Hyundai plant, Sriperumbudur at the right on the NH4 highway, you will see sipcot Chennai on the left afterwards and an ICO pump on the right. Take the first right onto Kundrathur Road, adjoining Katchipedu town. There's also one road before, leading to the JJ Govt High school (dont take this one). If you have reached Rajiv Gandhi Memorial you have driven further.
b) After crossing Katchipedu, you will immediately see a road deviating to the right leading to manimangalam- tambaram, driving straight on this road you will pass trough small villages before hitting a Manimangalam and a T-Point after you cross the town , take a right from here, you will see Darmeshwarar Temple on the left, keep driving adjacent to the lake till you hit a wider road in front of you, a T-point again.
c) Take a Left on this road, keep driving straight till you hit the Valdalur Railway crossing, you have reached GST road NH45 after the railway crossing, take a left onto GST road.
d) You will reach Vandalur Zoo on the left.Take the left turn on the road after the Vandalur Zoo and between Crecent School and University campus, go straight on this road.
e) You will cross Super forge and Sri ramanujar Engineering college on the right and then Tagore Engineering college on the left. You will see Krisp IT park after some distance on your left and then cross Texx One (P) Ltd, there is a 4-way crossing, just keep going straight till you reach a T-point, take a right into Kelambakkam and then first left , you will cross a canal and reach the ECR, right towards Mahabalipuram and left towards chennai.
This route dives 45 deg touching the Vandalur Zoo therefore will save time, provided road conditions are suitable. Though, the first route is much simpler to follow.
btw, how Mamalla resort, currently exploring all options suggested and found before finalizing
