Hello Saida S,
The i.MX6DualLite and the i.MX6Quad are pin-to-pin compatible, provided that some design decisions are followed. You can see Application Note 4397 (link below) for more details.
https://www.nxp.com/docs/en/application-note/AN4397.pdf
The hardware requirements are in section 4 of the application note. Its recommended to design with the possibility to migrate to a smaller pin-to-pin compatible processor if you are interested in doing so at some point. If your design is done for the i.MX6Q it’s possible that you will need to make some layout changes if you didn’t follow the guidelines listed on the application note.
I hope this helps!
Regards,
