Harish sits on the right of Satish. Satish sits immediately between Manish and…

In a single-row seating puzzle, the clue "X sits between Y and Z" places X immediately adjacent to both Y and Z, forming a fixed block of three consecutive seats with X in the middle; a clue "A sits to the right of B" then fixes where any remaining person can go relative to that block.

Here, Satish sits immediately between Manish and Girish, so Manish, Satish, and Girish occupy three consecutive seats with Satish in the middle - either as Manish, Satish, Girish or as Girish, Satish, Manish, read left to right. Since Satish is already the middle seat of this block, the only seat left for Harish is at one end of the row, outside the block. Harish sits on the right of Satish, so Harish cannot take the left-end seat (that would put him to the left of Satish); he must take the seat at the right end of the row. Both valid full arrangements are therefore Manish, Satish, Girish, Harish and Girish, Satish, Manish, Harish, and in each one Harish occupies the rightmost seat.

Checking back: in both arrangements Harish's seat is to the right of Satish's seat, and Satish sits directly between Manish and Girish - both clues hold, and no other person can occupy the end seat since Manish and Girish are fixed inside the three-person block and Satish is its middle.