How can i generate number for same piece of text using VS Code

You can use the extension Regex Text Generator

• select the word Greece
• select all cases you want with
  • Ctrl+D multiple times
  • Ctrl+Shift+L to select all
  • use Shift+Alt+Click to create multiple cursors
• if needed RightArrow to get all cursors after the word Greece
• execute command: Generate text based on Regular Expression (regex)
• As Original Text Regex use: .*
• As Generator Regex use: {{=i+1}} (watch the space as first char)
• Look at the preview, use Esc to cancel and Enter to accept

You can use any calculation based on i you want and you can also match number in the selected text and use that in the calculation N[...].

You can also add the word Greece by using Greece {{=i+1}}

You have a couple of options. First, using the extension, Find and Transform (disclaimer, I wrote that extension, this is very easy. Make this keybinding in your keybindings.json (after installing the extension):

{
  "key": "alt+n",          // whatever keybinding you like
  "command": "findInCurrentFile",
  "args": {
    "find": "(alt=\"Greece\")",
    "replace": "$1 ${matchNumber}",
    "isRegex": true
  }
},

Actually you can make it even easier if you first select what you want to modify (see the demo below). Then use this simple keybinding:

{
  "key": "alt+n",
  "command": "findInCurrentFile",
  "args": {
    "replace": "$1 ${matchNumber}",  // what you select will be put into $1
    "isRegex": true
  }
},

Another option - not quite as easy

Snippets have a variable $CURSOR_NUMBER which is useful here.

Make this keybinding:

{
  "key": "alt+n",
  "command": "editor.action.insertSnippet",
  "args": {
    "snippet": "$TM_SELECTED $CURSOR_NUMBER"
  },
  "when": "editorHasSelection"
},

1. Do a find on your desired text match: alt="Greece"
2. Ctrl+Shift+L to select all occurrences of the find match.
3. Trigger the snippet via its keybinding.

Demo of this method:

So this second method is more steps but doesn't require an extension.