<p>Yes, the same project can be (and many are) submitted to Intel, Siemens, -and- ISEF. The same project can even go toward other competitions such as YES and JSHS, too, provided your research topic falls within the ground covered by every competition.</p>
<p>As for how long it takes to have “submit-able research,” sometimes it takes only the course of a single summer, though that’s more rare, and obviously, the longer the project has been ongoing, the more (significant) results you will have.</p>