When Restrict activates its effects and selects great maju garzet, when its attack is 2000, does restrict then have 2000 attack even though it says 0 on the card. The reading on restrict stats that it doesnt have to be the original attack.

I think the attack of TER would become 0....................

Thousand-Eyes Restrict would have 0 ATK and 0 DEF. Any effects or ATK/DEF modifiers that were effecting the monster that equips Thousand-Eyes Restrict no longer do, so the ATK and DEF values it gives would be those printed on the card.