Hi Rohit,

Too happy to see someone so planned and focused for a better future prospects at a young age.

I have no clues of what Aptitude you are talking about.

To become a successful Hotel manager, one needs a pleasent personality, good communication skills, empathy and needs to be social.

As far as being weak in grammar is concerned, you can begin to improve on that by conversing more with people in English, and a lot of reading and at the same time articulating what you read.

In terms of GK, I have no clues what you mean here. When we say a manger needs to be well versed with GK, they are more related to the workings that happen in the hotel business, equipment's needed and a little knowledge how they function and as well as being like a tour guide.
Tourist information like places to visit, means of transportation, a little history about the place etc.

This kind of information can be available on the net and if you are interested a little reading can help also. Surfing the net will also help you get knowledge on this area.

As far as GK in general is concerned, reading is the only key to this answer.

You have a lot of time to prepare.

Currently it would be the best for you to focus on your 10th class preparation.
Though preparations does not mean that you can skip reading.
Take out little time, read newspapers and try and discuss those articles with friends or teachers, who can help you improve on your necessary skills.

Hope this helps.

Wish you good luck dear............