How can I make my credit score jump a hundred points the fastest so I can get approved for a loan to buy a house in USA

It’s simple.

I’ll assume that you have few, if any late payments showing on your credit report. If there are a couple, don’t worry about it. As they get older, they’ll have less effect on your score. A 30-day late payment that happened two years ago will typically affect your score just a couple of points.

To maximize your scores, do the following:

• if you have any collection accounts newer than two years, arrange to pay them off. Negotiate with the creditors if possible, but pay them off. If they are older than two years, leave them alone. Changing the status from “open collection” from three years ago to “paid collection” this month will cost you dearly in points on your score.
• Pay all your credit cards down below 30% of the credit limit. Ideally, pay them off because of the high interest rates, but 30% is the magic number.
• If you plan to buy within 6 months and you have “thin” credit (few open accounts), consider applying for two or three other credit cards, even if one of them is a secured card. As long as the institution reports to all three bureaus, a secured card will have the same positive effect on your score as unsecured ones. Use them for your regular purchases and pay them off in full each month—carrying a balance is expensive and does not help your score in any way.
• Don’t close any revolving accounts. The older accounts are, the more they help your scores.

As I said: simple. Paying down revolving debt is the single fastest way to boost your scores.