This tutorial uses ArcMap version 10.2. Some features may be absent or behave differently in other versions. If you need assistance with a different version of ArcMap, please contact ESRI support. This example shows a 5-band GeoTIFF (RedEdge camera).
If you don't use ArcMap or are using QGIS see this article.
1. Open your data from the Catalog
Connect to the folder containing your GeoTiff using the 
option. Then, use the 
next to your Geotiff to expand the view so you can see all 5 individual bands, like so:
Now, click and drag bands 3 (Red), 4 (RedEdge), and 5 (NIR) into the Table of Contents Window. If the Table of Contents is not visible in your window, you can open it by going to Windows>Table of Contents.
2. Turn on “Spatial Analyst” Extension
Go to Customize>Extensions to open the Extensions menu. Ensure that “Spatial Analyst” is checked. Click Close.
3. Open Raster Calculator
Open the ArcToolbox by clicking the 
option in your main toolbar, or by navigating to Geoprocessing>ArcToolbox. Then, navigate to the Map Algebra tools within Spatial Analyst Tools. Click on “Raster Calculator” to open the Raster Calculator.
4. Do the Math!
Use the raster calculator to perform the necessary band math. Use the “Layers and Variables” menu to add the necessary layers into the expression box. Double Click on the Layers and Expressions to add them into the expression box. Ensure that each layer is surrounded by a Float expression when performing band math.
For NDVI, you should have an expression that looks similar to this:
For NDRE, you should have an expression that looks similar to this:
The Formulas for NDVI and NDRE are as follows:
5. Change NDVI layer properties to approximately match Atlas view
Right click on the layer, and go to Properties. Navigate to the Symbology tab, and click “Classified”. Change the number of Classes to 11, change the color ramp to Red-Yellow-Green, and click “Classify”. Within the Classification window, double click on each of the break values, and manually change them to 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, and 1. Click OK.
Back in the Layer Properties window, double click on the red box under the “Symbol” column. Select No Color. Your window should look similar to this:
Now, hit Apply.
6. NDRE Layer Properties
At this time, ArcMap does not include a default color ramp that matches the color ramps seen in the Atlas NDVI2 and NDRE layers. For best results, we recommend choosing a color ramps and class breaks that best suit your visualization and analysis purposes.