Punctuating local area names

Names of places, including neighborhoods in cities, are often capitalized, according to the Chicago Manual of Style.

Thus Chicago has the Loop, the Near North side, the Magnificent Mile.

Your local newspapers probably have their own conventions for capitalization of parts of the city whose designations have become proper names, which you can discover by reading a few issues of the papers, especially the real estate sections.

If you’re writing for a local audience, following local conventions is a good idea. For a wider audience you may have to explain what the place name means.

This Wikipedia page https://en.m.wikipedia.org/wiki/List_of_Indianapolis_neighborhoods has a list of Indianapolis neighborhoods, but doesn’t include near Eastside.