Hi Ritesh,
As Sade Sati has already started for your brother, so tell him to do some good deeds, respect elders and always favor justice. After approximately one year, the testing time will start for your brother on the affect of sade sati. To reduce those effects he can reading Hanuman Chalisa and visit Hanuman / Shanishwar Temple on Saturday evenings and offering black sesame (tila) seeds.
Along with that, on fortnightly on Saturdays heat an steel black colored griddle (tava), after it gets heated take out the tava griddle (tava) and above it sprinkle few drops of milk by worshiping lord Shani / Saturn. And also ask him to offer some food for black crows. These remedies should be followed for next 5 years to overcome the difficulties.
To get a good match for your brother ask him to chant below mantras on every Friday in evening at any goddess temple for atleast 6 times:
OM DRAM DREEM DROUM SHA SHUKRAYA NAMAHA!!!
Along with this, he has to worship Narasimha Deva / Kartikeya (Murugan) every Tuesday and offer red flowers and chant below mantra for minimum 9 times:
OM KRAM KREEM KROUM SHA BHAUMAYA NAMAHA!!!
If possible, he should wear diamond on his right hand little finger. If you cannnot afford one at least get him a Natural White Zircon or Synthetic Cubic Zirconia (also known as CZ and American Diamond) of 2, 4 or 6 carat. Synthetic Cubic Zirconia is not too costly, it may cost you around 1000 INR for a standard AAA quality gemstone; however it is a man-made gemstone (but something is better than nothing).
It is better not to delay and ask him to start following above suggestions as soon as possible.
GOD BLESS!!!
Srinivasa Temkar