Do I have to file I-130 and I-864 together for my brother who is in US on H1B visa?

There is no reason to file I-864 with an I-130 petition: I-864 will not be considered. Form I-864 Affidavit of Support has to be filed with Form I-485 Application to Adjust Status. I-485 cannot be filed until an immigrant visa is available for the beneficiary. Only spouses, parents, and children of U.S. citizens can file I-485 applications together with I-130 immigrant petitions. In F4 category (brothers and sisters of U.S. citizens), the earliest time an immigrant visa might become available is in October 2027; if your brother is a citizen of Mexico, he will wait for his immigrant visa 5 years longer; if he is a citizen of Philippines - 11 years longer, until 2038. If your brother files I-485 application together with your I-130 petition for him, USCIS will deny the application (and will not return the fee you will pay for filing Form I-485). Please understand that the filing of your I-130 petition does not give your brother the right to remain in the U.S. until his time to receive an immigrant visa comes. If your brother stays in the U.S. after his authorized stay in the U.S. expires, he will become illegal and will not be able to receive a green card even when an immigrant visa will become available to him.