Can I install sis-file in my lg neon 2 phone?

If your friend has got some other phone irrespective of the company and the model and is capable of running an .sis application, you should let his phone be and concentrate on your phone's technical specifications.

Its time for revealing the crown jewel fact:

Your phone LG Neon II is a JAVA class phone or J2ME i.e JAVA 2 Micro Edition class. This J2ME consists of programming specifications and a special virtual machine, the K virtual machine, that allows a J2ME encoded program to run on your mobile device.

So, it won't support .sis applications as SIS is a Symbian OS archive file.

You better forget about .sis applications as your phone will support only JAR and its sister class files. Do not worry if your phone does not support SIS, JAVA is no doubt one of the greatest pioneers in mobile and computer application field and they too have Class A range of mobile applications. Also maximum websites provide content for both JAVA and Symbian platforms. So you can download stuffs as per as your requirement and convenience.

Good luck for your LG Neon 2 and I hope that you find this article useful.