Q. My daily use 70 km and I have lumbered spondalysis so which bike is suitable for me Unicorn 150, Avenger 160 ya Classic 350?

Try to reduce stress on lower back and on joints by leaning backward.In that sense bikes with recumbent style is preferred.In your options Bajaj Avenger suits. However its your choice..😄

Avenger is more suitable.

Suggest you take advice of your Doc for riding a 2-wheeler as any 2-wheeler is not bereft of jerks which is not good for your spinal chord.