Sad Hi all.. i need urgent help :(

It could very well be that they inhaled smoke. In which case I'm not sure what can be done to repair that kind of damage. That said, both the things you describe sounds like they can also have unrelated causes. I have heard mention here that it's nearly impossible to find exotic vets in India but that is really what they need right now. The head tilt indicates an ear infection or ear mites, you will need to find a vet to prescribe antibiotics or if it's ear mites it can be treated at home with Ivermectin but before you do, make sure they give you the correct antibiotics because vets are renowned for giving the wrong or harmful antibiotics to guinea pigs. So please do your research here:

https://www.guinealynx.info/dangerous_medications.html
https://www.guinealynx.info/medications.html
https://www.guinealynx.info/emergency.html#ear
[url]https://www.guinealynx.info/earmites.html
https://www.guinealynx.info/ivermectin.html[/URL]

The weight loss can indicate many things, none of which are good. What are you feeding them exactly? Just so we can rule out an issue with the diet. Other than that, she could have an issue with her teeth that need to be checked out but you say she's eating fine. Does she have any other symptoms? Check here:

https://www.guinealynx.info/emergency.html

A common treatment for animals who inhaled smoke is oxygen, since inhaling smoke coats our lungs and hinders oxygen intake. You can buy "oxygen in a can", or a local medical store may carry tanked oxygen.
Get aTupperware or other container, and rig the oxygen to the container with her nose inside. Like an oxygen mask.
Or you can put her in a large large container with it. That may help...