Set a video to play from certain time

To have a video start playing from a specific point, add "#t=" to a video's embed code, followed by the time at which you'd like the video to begin playing.

For example, if you want a video to start at 2 minutes and 30 seconds into the video, your embed code would look something like this:

    <iframe allowfullscreen="" frameborder="0" height="315" src="http://www.youtube.com/embed/UkWd0azv3fQ#t=2m30s" width="420"></iframe>

make an embedded video autoplay

To make an embedded video autoplay, add "&autoplay=1" to the video's embed code immediately after the video ID (the series of letters that follows "v/").

Embedded videos that are autoplayed don't increment video views.

Example:

    <iframe width="560" height="315" src="
    https://www.youtube.com/embed/D6Ac5JpCHmI?&autoplay=1" frameborder="0"
    allowfullscreen></iframe>
Regards:
https://support.google.com/youtube/answer/171780?expand=PrivacyEnhancedMode#privacy

privacy-enhanced mode

When you turn on privacy-enhanced mode, YouTube won't store information about visitors on your website unless they play the video.
यानि YouTube हमारे website के सिर्फ उन्हीं visitors की सूचनायें रखेगा जो विडियो को play करेंगे

Embed videos & playlists

click here to watch in details on YouTube
https://youtu.be/eroT4Fh4QIU

Embed a video

    On a computer, go to the YouTube video that you want to embed.
    Under the video, click Share .
    Click Embed.
    From the box that appears, copy the HTML code.
    Paste the code into your blog or website HTML.

Embed a playlist

    Sign in to your YouTube account on a computer.
    On the left-hand side of the page, click Playlists.
    For the playlist that you want to embed, click its title.
    Click Share .
    Click Embed.
    From the box that appears, copy the HTML code.
    Paste the code into your blog or website HTML

Regards:
https://support.google.com/youtube/answer/171780?expand=PrivacyEnhancedMode#privacy