Neethaane En Ponvasantham Songs from a Rhythm (Thalam) and Scale (Ragam) perspective !!

Saaindhu Saaindhu - 4/4 Adhi Thalam Chatushra Nadai (goes as 3+3+2)
Composed in D Major , takes the ragam of Mohanam predominantly (there is an accidental Ni note too) , during the Charanam it changes to B Minor (Scale of Natabhairavi) but has a distinct Suddha Dhanyasi flavour.

Kaatrai Konjam - 7/8 Misra Chaapu
Composed in E Major (Shankarabaranam) , shifts to its relative C# Minor during the Charanam and becomes Keeravani. At Saathi Vaitha , it returns back to the scale of E Major but instead is based on the Harmonic Major scale which is Sarasaangi.

Mudhal Murai - 4/4 Adhi Thalam Chatushra Nadai
Composed in B Minor in the ragam of Natabhairavi (Ni3 is also used at times giving an extra effect)

Vaanam Mella - 4/4 Adhi Thalam Tisra Nadai
Composed in F Minor , takes the raga of Pushpalathika as it mostly avoids Dha. Uses swing rhythm which may be confused as 6/8.

Pidikkala Mamu - 4/4 Adhi Thalam Chatushra Nadai
Pidikala Mamu is composed in E Major (Shankarabaranam) , Vidhi Pathadhe is in 6/8 and composed in A# Minor and follows Madhyamavathi Ragam

Ennodu Vaa Vaa - 4/4 Adhi Thalam Chatushra Nadai
Composed in E Minor and follows Natabhairavi Ragam

Pengal Yendral - 4/4 Adhi Thalam Chatushra Nadai
Composed in B Scale and follows the ragam of Gowri Manohari

Sattru Munbu - 4/4 Adhi Thalam Chatushra Nadai
Composed in D Scale , difficult to slot into a raga as it uses almost all notes but is predominantly in Keeravani

Note : These are not completely accurate and its definitely possible that there could be mistakes. Its just an enthusiastic attempt on my part to slot the songs based on my understanding into different raga and tala patterns.