Well if it is your local manufacturer and there's not much choice you should probably trust them, I googled your previous pellets Agrosomething they are specialising on food for animals and from their other products I believe that it's not for pet rabbits but for farming, but I can be wrong. I understand that you depend on your parents, there are many online shops like zooplus.com that ship to Estonia 5 euro for delivery and free delivery on orders over 50 euro or so, no problem and they have pet rabbit food and everything for rabbits so you can get all ingredients and choose proper food for your rabbit. But, of course their prices would be much higher than your father got from your local manufacturer, so maybe they won't buy from them. I know I am sometimes on a very tiny budget myself can't afford everything I wish to buy for my rabbits, so I understand that pretty well.
About your food. If I were in your situation I would probably try to find the name of manufacturer and call them and ask about rabbit food they produce, they probably would redirect me to some other people who are responsible for this particular food, maybe it's just dead end but I would try anyway. Just to get what it made of.
Now, say I have a bag of new food and I have a rabbit I would probably I don't know I'd give him some, firstly mixed with his old pellets (also unknown brand and ingredients), well he will probably eat them as well.
The problem is not that he won't eat them but maybe they are high on calcium or composed of ingredients simply not good for his bones or liver or hair or something, home rabbits can live 10-14 years on good diet and proper care, but they also can develop arthritis or teeth problems or liver problems, and you will have to go to vets, which is not easy as I understood and would be very expensive so you again will depend on your parents with that.
That's why people here won't recommend feeding him some unknown food, because well-known manufacturers produce well-balanced food, to keep your rabbit healthy for long and happy life.
That is your risk, that if this food made for meat rabbits maybe their main goal is to gain more weight and I don't know at what age they are going to be butchered but definitely not 10 years.
That's how I see it, I might be wrong. You will have to think for yourself and decide on your own responsibility.
If you won't feed him dry food I think there are more options I know there are different types of diet and maybe some people here can advise about it, I have no experience, my rabbits are 100% home pets and my situation is different. But I am happy to share what I've already learned myself, pretty sure you'll find your own solution.