Default [Q] How to install stock ROM on iBall Andi 3n?

Hello there,
I am trying to install the stock ROM for my iBall Andi 3n since months. iBall Andi 3n is manufactured by iBall, India and is an MTK6575 device. I used the stock ROM provided at this page . I have tried different versions of SP Flash tool's ranging from 2.x to 5.x. Generally on SP Flash tool 3.x, for example on 3.1224.0, after I select the scatter file from the ROM image, I get the following error after I load the scatter file and press "Download" button.

I tried to copy the addresses provided in checksum.ini file in stock ROM's folder to checksum.ini file in SP Flash tool's folder. Also I created a CWM for my device using the boot.img image from stock ROM and the CWM works. I selected the stock rom's .zip file from SD card and it aborts installation.

What's wrong here?
Is the stock ROM wrong/corrupted? (I tried downloading it many times from various sources)
Is there some problem with my phone?
Is there some problem with my Windows 8.1 Update 1? (I think I have the necessary drivers, I can use adb from windows command prompt and it detects my device)

If the stock ROM is incorrect, can someone create a similar custom ROM for my phone using the boot.img file from stock ROM?

Any help appreciated.