Some closing parentheses are missing.
Also, you are reusing self.l5, which should probably be self.l6 for the calculation of x50_.
This code should work:
  def forward(self,x):
    x200=self.d2(self.b2(F.relu(self.l2(self.d1(self.b1(F.relu(self.l1(x))))))))+x
    
    x100=F.relu(self.l3(x200))
    
    x100x=self.b4(self.d4(F.relu(self.l4(self.b3(self.d3(x100))))))+x100
    
    x50=F.relu(self.l5(x100x))
    
    x50_=self.b6(self.d6(F.relu(self.l6(self.b5(self.d5(x50))))))+x50
    
    x10=F.relu(self.l7(x50_))
    
    return x10

PS: I’ve formatted your code so that I could easily copy it. You can add code snippets using three backticks ```