So, when Google launched new series of cheap and budget handsets (Android One) they stated that all the headsets with android one will get all updates by Google.
So now handsets with android (Micromax Canvas A1, Karbonn Sparkle V and Spice dream Uno) are going to get lollipop update. This news got confirmed when Spice’s Facebook page updated

“Your rocking weekend starts…Spice rolls out Lollipop 5.1 update for Spice Dream Uno users. Check NOW!”

Similarly Micromax said that Canvas A1 handsets users can follow the below instructions to install Android 5.1 Lollipop on their handsets.
“Canvas A1 with Android One should at least have 30 percent battery to install the OS. Users would have to connect to a Wi-Fi network, check for system updates under the handset’s Settings option, and download/ install the package if available,” the company said.

While both companies did not stated that what changes will the new update bring but it will get all the basic changes that come with the lollipop update and it will also improve performance and app crashes.