Q:

How I can perfomance a GLM with several independent variables

I need to performa a GLM for several independent variables for a Gaussian family, something like this:
$y$~$x_1+x_2+x_3+x_4+x_5+x_6$
how i can do this? 
thanks a lot for any help

A:

Firstly store your data into a dataframe.  You can do this as follows
dat <- data.frame(y=y,x1=x1,x2=x2,...,x6=x6)

Next decide what kind of GLM you want to fit, and also what link function you want to fit. 
Then use R code of the form
glm(formula, family=familytype(link=linkfunction), data=)

So for example
model <- glm(y ~x1+x2+x3+x4+x5+x6, family=gaussian(link=identity),data=dat)

data=dat is optional. 
I would recommend searching crossvalidated before asking questions in future.  A massive amount of questions on fitting GLM's exist with very well written answers.