The classic teacher farewell gift is a pen, and it stays the classic for good reasons: it is unsized, has no colour to get wrong, is recognisable enough that its value is obvious when the box opens, and it sits on a desk where it keeps being used. If a class is pooling money and nobody can agree, the pen set is the answer that nobody regrets.
Beyond that, the categories that suit this occasion are the ones that follow a teacher home rather than to another classroom — coffee, a piece of luggage. That is worth thinking about, because a farewell often coincides with retirement, a move, or a change of school, and a gift that assumes another classroom can land oddly if it is none of those.
One practical note on sourcing this band. Desk pieces, photo frames and planters — the obvious teacher gifts — mostly sit below ₹3,000, so at this level you are choosing between writing instruments, warm drinks, luggage and electronics. If your collection lands nearer ₹1,000, buy a good desk keepsake rather than stretching to a weaker item at this price.
And whatever the class buys, have everyone sign something. A card with thirty specific lines in it outlasts the gift, and it is the part a teacher actually keeps.