You can use basket orders to buy Nifty and Bank Nifty options outside the allowed range by creating a hedged position. To do this, first add the short/sell order in the basket, followed by the buy order next.
The sell leg entry may require a slightly higher margin initially. However, the final margin will be blocked based on the hedge after you add the buy leg.
You can effectively hedge your positions because Zerodha allows long positions of any range as long as their count equals the short futures or options positions you hold in your account.