Notice the following timing when Christ's Apostles sit upon the 12 thrones Jesus promised them...
Matt 19:28
28 And Jesus said unto them, "Verily I say unto you, That ye which have followed Me, in the regeneration when the Son of man shall sit in the throne of His glory, ye also shall sit upon twelve thrones, judging the twelve tribes of Israel.
KJV
If Lord Jesus were sitting upon His throne of inheritance already today, then His 12 Apostles should also be sitting upon those 12 thrones on earth, over the 12 tribes of Israel.
So no, Lord Jesus is not sitting upon His throne of inheritance today, which the throne He is to inherit is David's throne, an earthly throne. Jesus is sitting at the right hand of The Father's throne today, expecting, till all His enemies are made His footstool, which is about His future Millennial reign of Rev.20 and Zechariah 14.
Really? Jesus isn’t seated at the right hand of the Father?
Colossians 3:1
Since, then, you have been raised with Christ, set your hearts on things above, where Christ is, seated at the right hand of God.
Ephesians 1:20
20 he exerted when he raised Christ from the dead and seated him at his right hand in the heavenly realms,
Hebrews 1:3
. 3 The Son is the radiance of God’s glory and the exact representation of his being, sustaining all things by his powerful word. After he had provided purification for sins, he sat down at the right hand of the Majesty in heaven.
Hebrews 10:12
12 But when this priest had offered for all time one sacrifice for sins, he sat down at the right hand of God
The scriptures disagree with you