This question had me scratching my head. Yeah, how come WordPress doesn't support this natively? And then I found out.
You asked how to upload SVG in WordPress 4.9.8 (the current version at the time of writing). You mention that you "tried uploading after installing different plugins". You don't say which plugins, nor whether they relate to SVG.
As I understand the situation, the safest, most appropriate, answer at this time is to use SVF Safe (a plugin written for this very purpose) by Darrell Doyle. If this plugin doesn't work for you, then I'd suggest that you have a conflict elsewhere, and you should follow the usual procedures for resolving that. Personally, if this plugin didn't work for me then I'd give up on the notion of uploading SVGs.
If you haven't already done so, may I suggest reading "SVG Uploads in WordPress - the inconvenient truth" by Bjorn Johansen and/or "How to Safely Enable WordPress SVG Support - 2 Simple Clicks" by Brian Jackson. At least you should know what you are letting yourself in for.