Hi all,

First of all, sorry if I am in the wrong section, I am first time on this forum ^^

I have a normal `mountain` bike for every day cycling...Yesterday, during the ride, my rear derailleur snaped....
Me having no idea in bikes, I am looking after some help.
I found "Shimano Tourney Rear Derailleur RDTX31G" on amazon for 10 pounds but I have no idea how they differ and will it fit my bike?
I have 6 `cogs` on the back which would mean 6 gears?

My questions are, will this part fit or which would and which would not?
What else will I require to change it, any other parts needed?
Will I need to buy a new chain or just buy chain disassemble tool and re clamp it back?
What tools will be required? Because I live in uni and I dont have my tools with me, so I will have to purchase them.

I am trying to fix my bike as cheap as possible so please bear this in mind.

Thank you, hope to hear some help from you guys

P.S - Picture attached just in case anyone wants to see it.