Yes, and it is never a mystery — the screen always shows the lowest amount you can bid right now.
The two numbers
The starting price. Where bidding opens, set by the seller. The first bid has to be at least this. The screen says Bidding starts at {price}.
The increment. How much each bid has to clear the last one by. If the top bid is ₹1,000 and the step is ₹50, the next valid bid is ₹1,050.
What the step usually is
Unless the seller sets their own, it is 5% of the starting price, with a floor of ₹10.
So an item opening at ₹500 steps in ₹25. One opening at ₹100 steps in ₹10, because 5% would be ₹5 and the floor lifts it. One opening at ₹20,000 steps in ₹1,000.
A seller can set a different step on their own auction, so always read the screen rather than doing the arithmetic.
Why a bid can bounce
A bid below the next valid amount is not a low bid. It is not a bid.
That is the single commonest confusion in a live show: somebody types ₹1,010 against a ₹1,050 next step, nothing happens, and they conclude the app is broken. Did my bid count?
The way to avoid it entirely
Use the Bid button rather than Custom bid. The button is always the next valid amount, so it cannot be rejected.
Custom bid is for jumping — going to ₹2,000 when the step would take you to ₹1,050, which is a real tactic for signalling that you are not leaving. It costs you more than you needed to pay if nobody was going to follow you.
Is there a maximum?
Not a limit on what you can bid, no. There is a separate thing called a maximum bid, which is the most you are willing to pay — your own ceiling, set by you, that Metzee then bids up to on your behalf. What a maximum bid is.
More: how bidding works, how to price for auction, how auctions find a price.