How to create a reference grid in QGIS print composer?

I wrote a QGIS plugin for this very use case, called Create Indexed Vertex Grid.

It works like the standard Create Vector Grid (Polygons) but assigns names to each cell in a spreadsheet-like format. It can also add label tabs on the top and left. You can use the name and isLabel fields to style the grid and headers.

It can be a bit finicky to use it with Print Composer, though, as you need to manually copy the extents over (using the layer metadata to get the bounds, and pasting into the extents on the Print Composer)

I believe there is a similar option to create Grids like ArcGIS in QGIS print Composer known as Draw Grid. Where you can give all kind of styles,distances between grid lines or Coordinate precision. You need to change the Default CRS to your project CRS.

Check the following link, I hope you will get the solution for your problem. Check from step 21 in Grid lines in QGIS composer

Thanks.