Is Mirae Asset growth the best Tax Saver Mutual Fund?

Is there any other best?

You picked the best as per my outlook.

I placed the order at 1 AM today (night), at what NAV the units will be bought?

See this - What is the cut-off time for mutual fund transactions on Coin?

So, it is the closing price of today?

yes right.

It is still showing as “Remarks - Order sent to AMC” and “Processing”.

Why is that?

It means Zerodha has sent the order to the mutual fund company (AMC) Mirae Asset. AMC mostly take few hours to confirm the units allotment.

What do you feel about the Quant Tax Plan (ELSS) Fund and IDFC Tax Advantage (ELSS) Fund?