Warning in install.packages : package ‘NonlinearTSA’ is not available (for R version 3.5.1)

[Timesaver]

Use a newer R version as I suggested in the previous post. The warning messages are clear.
Latest R with latest rtools.

[andresrcs]

Now you are having connectivity issues, R is not being able to connect to the CRAN repository you have selected, these are some things to try.

• Choose a different CRAN repository, RStudios repository is a good choice (http://cran.rstudio.com/) or you could choose one that is geographically closer to you.
  
  
• Disable secure download setting.
  
  
• Check if your internet connection has traffic restrictions of some kind, like a firewall, proxy server, etc. This is usually the case when you are at work or school.

But, I also agree with @Timesaver, you should consider updating your R version, at will make things easier for you in general.

Note: Please do not post screenshots, they are considered a bad practice here, post the console output as formatted code instead, here is how to do it:

FAQ: How to format your code

Formatting Code: the Basics All code or console output you include in your posts should be formatted properly. Luckily, this is very easy to do! Just use the code formatting button at the top of the post editing box: [image] Select some code Click the </> button! The code formatting button automatically adds special Markdown formatting symbols to whatever you selected. If you check the preview pane to the right of your post, you'll see that the forum software now outputs nicely formatted code . [04] The code formatting button is pretty smart! It can tell the difference between snippets of code that are part of a sentence and blocks of code that stand alone. …

[Somaira54]

Hi faparvez, the latest version of R is 4.0.4. If your computer is compatible with this version of R, try to install this version. Maybe then the package could be downloaded. Good Luck
Somaira Azam