crontab run every 15 minutes between certain hours

Yes, that's correct.

The entry in crontab would should be:

*/15 7-19 * * * /path/script >/dev/null 2>&1

Your command is fine!

To run from 7.00 until 19.45, every 15 minutes just use */15 as follows:

*/15    07-19        *     * *     /path/script
^^^^    ^^^^^

That is, the content */15 in the minutes column will do something every 15 minutes, while the second column, for hours, will do that thing on the specified range of hours.

If you want it to run until 19.00 then you have to write two lines:

*/15    07-18        *     * *     /path/script
0          19        *     * *     /path/script

You can have a full description of the command in crontab.guru: https://crontab.guru/#/15_7-19___