Lumia 435 is great, its camera is just acceptable. Display sharpness is great (233 PPI), display colors are good. 1GB ram with Windows 10 support. Smart dual sim.
In speed and performance, it even beats Grand Prime, Grand 2 and S3 (I9300, 1GB ram) !.
Lumia 435 is a great choice in around 10000.
Lumia 540 is great in around 16000.
In least price, the best performance 'lag free' phones are no doubt windows phones!
In android, starting good dual sim phone is Galaxy Core Prime Dual sim. Do NOT go for anything below Core Prime in Samsung, as they are all junk.
They all have great battery timings too.