Need help updating htc m8 to marsh mallow

[samsexy]

I got htc one m8 4days back from a store in hyderabad. Everything is great about this device but there are two major problems i am facing.

1 - There is no software update option in the phone.

2 - Not able to access 3g or 4g, only 2g coming.

So i need help on these two points and I am desperate about it.

I got some info about the device that its a rooted device having s off and bootloader is locked.

So Please guide me how to overcome my issue, it will be a big help.

I am not that much tech expert but if you can guide me i can do it.

Thanking you.

 

[redpoint73]

The device doesn't support you carrier. You shouldn't have bought it, without knowing in advance whether it would work on your carrier, or researched if/how it can be modified to do so.

The device can be modded, yes. Definitely for 3G, LTE is not certain.

You'll need to find the firmware.zip that supports your local carrier's bands.