I'm afraid it might melt and ruin the psu (or the motherboard)
A weak cable will get hot enough and release magic smoke until it breaks itself. Your PC will try to source as much current it wants but the worse that can happen is it won't get it, so there is no chance of melting and blowing something in your PC. Only the power cable will get damaged.
Are you sure this cable will work?
As an electronics hobbyist, I can say if you want to test if that cable will be able to take the load or not, what you can do is, plug that cable in, boot your PC, put max load on, immediately place one hand on your PSU power button and in the other hand hold the power cable from the center point tightly, as soon as you feel it getting any warm or hot, you hit the kill switch.
It you don't feel any temperature change, the cable is fine for that load.
Now, if don't want to get into any of that mess, I can link you a real high quality cable, it will come from the overseas,
LINK
It's listed on mouser.in (
a place to buy all kind of discrete electronic components).
There is a site/company here in India, which will import this part and deliver it to you and they will take care of all the customs stuff. All you have to do is go to their site semikart.com and enter the part number which in your case is 693-3-101-514 . The cable will show in their site. It will cost you about 1660 including everything customs, delivery etc.
The catch it will take long time, can also take one month.
The datasheet of that cable -
LINK