Buy a bottle cutter on Amazon. There are several good ones.
Here is a good one ( click HERE) on Amazon.
Hi Izzah: Here are some sites that may help:
One of these should work for you:) Good luck
Here's some helpful instructions
try this: https://www.craftylittlegnome.com/cut-a-glass-bottle/
My husband has kindly cut glass bottles for me - it was little trial and error but the more he did the more he had a good neat cut https://vickymyerscreations.co.uk/tutorial-2/creative-things-to-do-with-glass-bottles-upcycled-cacti-planter/
You could try this: https://www.condoblues.com/2015/06/how-to-cut-glass-bottle-with-hot-water.html