IF YOU TOUCH UR BODY WITHOUT ANY SEXUAL DESIRE OR ATTACHMENT OR ANYTHING IS IT A SIN NO OR YES STRICTEST ANSWER POSSIBLE ITCHING THE MAIN PART I know it’s not pure but is it a grave sin

In the strict Jain view, touching your own body is not automatically a grave sin.

But:

• If it is done with sexual desire, lust, or attachment, it does create bad karma.
• If it is only to relieve an itch, pain, or discomfort, and there is no lust or enjoyment, it is not the same as a grave sexual sin.
• Still, because Jain Dharma values detachment from the body, even ordinary body-fixation is spiritually impure in a subtle sense.

So the strictest answer is:

No, not a grave sin if it is only for itching and without sexual desire. But yes, it is still spiritually not ideal, because Jain path aims at reducing attachment to the body.